Slow Cooker Mongolian Beef: Easy Recipe
Tender flank steak simmers all day in a sweet and savory sauce. This slow cooker Mongolian beef is pure comfort. Dinner .
Why You'll Love This Mongolian Beef
- •**Utterly Effortless:** Seriously, the slow cooker does all the heavy lifting. You just prep the ingredients, set it, and walk away. It’s perfect for those days when you just don't have the energy for a complicated cooking session.
- •**Melt-In-Your-Mouth Tender Beef:** The low and slow cooking process breaks down the flank steak until it’s so tender you barely need a knife. Each bite is just incredibly soft and succulent, it’s a texture you just can’t rush.
- •**The Most Dreamy Sauce:** Oh, this sauce! It’s deeply savory from the soy, with a lovely sweetness from the brown sugar and an aromatic kick from fresh ginger and garlic. It thickens into a beautiful glaze that coats every single piece of beef.
- •**A Home That Smells Amazing:** There is nothing quite like walking into a house that smells like a delicious meal has been simmering away for hours. It’s the ultimate welcome home, a sensory promise of the wonderful dinner to come.
*“This is the coziest, most delicious meal. It feels like a warm hug in a bowl.”*
Essential Ingredient Guide
- Flank Steak: Flank steak is my absolute favorite for this. It has a wonderful, beefy flavor and a texture that becomes incredibly tender when cooked slowly. The trick is to slice it very thinly against the grain—this ensures it will practically melt in your mouth. If you pop it in the freezer for about 20 minutes beforehand, it becomes so much easier to get those paper-thin slices.
- Low-Sodium Soy Sauce: This is a non-negotiable for me. Regular soy sauce can make the final dish overwhelmingly salty after it reduces in the slow cooker. Using a low-sodium version gives you all the deep, umami flavor but allows you to control the saltiness yourself. It creates a much more balanced and pleasant sauce in the end.
- Fresh Ginger and Garlic: Please, please use fresh here if you can! The vibrant, zesty aroma from freshly grated ginger and minced garlic is the heart of this dish. It provides a warmth and depth that you just can't get from the powdered stuff. That little bit of prep work makes a world of difference, infusing the whole dish with its beautiful fragrance.
Complete Cooking Process
- •**Don't Skip the Cornstarch Coat:** Tossing the beef in cornstarch before cooking is crucial. It creates a protective barrier that keeps the beef tender and is the first step to a thick, glossy sauce.
- •**Slice Against the Grain:** I know I keep mentioning it, but it's the most important step for tender beef! Look for the lines (the grain) in the meat and slice perpendicular to them.
- •**Fresh is Best:** Using fresh ginger and garlic will give you a much brighter, more aromatic flavor than dried powders. It's a small step that makes a huge impact.
This is the calming, methodical part of the process. You'll start by thinly slicing your flank steak against the grain, which is so important for tenderness. Then, you'll toss those beautiful ribbons of beef with cornstarch until they're lightly coated. This little step is the secret to both protecting the beef during cooking and helping to thicken that gorgeous sauce later. In a separate bowl, you'll whisk together the soul of the dish: the soy sauce, water, brown sugar, garlic, ginger, and a touch of sesame oil. The scent alone is enough to get you excited.
Now for the magic. You’ll gently place the coated beef into the slow cooker and pour that amazing sauce right over the top. Give it a gentle stir to make sure everything is acquainted. Then, you put the lid on, set it to low, and walk away. This is where the trust comes in. For the next several hours, your kitchen will slowly but surely fill with the most incredible, savory-sweet aroma. It’s a completely hands-off process, much like my favorite beef and broccoli recipe, but with its own unique, wonderful character.
After hours of anticipation, the beef will be impossibly tender. Now, it's time to transform the cooking liquid into a luscious, glossy sauce. You'll carefully ladle most of the liquid into a small saucepan on the stove. A little cornstarch slurry is whisked in, and within a minute or two of simmering, it thickens into a beautiful, velvety glaze. Pour this back over the beef in the slow cooker, add your sliced green onions, and give it one final, gentle stir. It’s a simpler finish than my Korean BBQ but just as satisfying.
Pro Tips for Perfection
These little details are what elevate a good meal to a truly great one. They're whispers of care that you can taste in the final dish.
Frequently Asked Questions
→Can I use a different cut of beef for this recipe?
Absolutely! While I love flank steak, sirloin steak or even chuck roast cut into cubes would work well. Sirloin will be similarly tender, while chuck roast will become more of a shredded, fall-apart texture after the long cooking time. Just be sure to trim any large pieces of fat before you start. It’s all about what you have and what texture you prefer in the end.
→How can I make this dish spicy?
Oh, adding a little heat is a wonderful idea. The easiest way is to add a teaspoon or two of sriracha or a pinch of red pepper flakes into the sauce mixture before you start cooking. You can also add some thinly sliced fresh chilies along with the green onions at the end for a pop of fresh heat. Start with a small amount and adjust to your personal preference.
→What's the best way to slice the beef so thinly?
My go-to trick is to place the flank steak in the freezer for about 20-30 minutes before slicing. You don't want it frozen solid, just firm to the touch. This makes the meat so much easier to handle and allows you to get those super thin, restaurant-style slices with a sharp knife. It’s a simple step that makes you feel like a pro.
→Can I make this Mongolian Beef gluten-free?
Yes, it's very easy to adapt. Simply swap the soy sauce for a gluten-free tamari or coconut aminos. They both provide that lovely savory, umami flavor. Just double-check that your beef broth is also certified gluten-free, and you'll have a delicious meal that fits your dietary needs without any compromise on taste.
→My sauce didn't thicken properly. What should I do?
Don't worry, that's an easy fix! It usually just means the sauce didn't get hot enough or needs a tiny bit more cornstarch. If it's still thin after simmering on the stove, just make another small slurry with about a teaspoon of cornstarch and a tablespoon of cold water. Whisk that into the simmering sauce, and it should thicken up beautifully within another minute.
→Could I add vegetables to the slow cooker?
You can, but timing is key! Heartier vegetables like carrots or sliced bell peppers can be added in the last hour of cooking so they don't turn to mush. For more delicate vegetables like broccoli florets or snow peas, I recommend steaming or sautéing them separately and stirring them in right at the end to keep them crisp-tender and bright green.
→Is this similar to other slow cooker beef recipes?
Recipe Origin & History
Despite its name, Mongolian Beef is not a traditional Mongolian dish. It's a popular staple of Chinese-American restaurants, likely developed in Taiwan in the mid-20th century. Its popularity comes from its wonderfully balanced sweet and savory sauce and incredibly tender beef, a combination that has become a beloved comfort food across North America. This slow cooker version adapts that restaurant favorite for the home cook, making it even more accessible and tender.
Skill Level Explained
This recipe is rated as 'Easy' because the vast majority of the work is hands-off. The preparation involves simple slicing and mixing, with no complex techniques. The slow cooker handles the entire cooking process, making it a very low-stress, high-reward meal that is perfect for beginners or anyone looking for a simple, delicious dinner.
Best Season to Make
This is truly a year-round comfort dish. Its warmth and richness are incredibly cozy during the fall and winter months. However, because it doesn't heat up the kitchen, it's also a perfect, effortless meal for a busy summer evening when you'd rather be outside than standing over a stove.
Taste & Texture Profile
Taste:
A deeply savory and sweet flavor profile, led by rich soy sauce and brown sugar with aromatic notes of garlic and ginger.
Texture:
- Outside: Coated in a silky, glossy sauce
- Inside: Incredibly tender, melt-in-your-mouth
- Bite: A soft, yielding bite with no chewiness
Velvety, tender strips of beef enveloped in a smooth, thick glaze.
Make Ahead Tips
You can do most of the prep a day ahead. Slice the beef and store it in an airtight container in the fridge. You can also whisk together all the sauce ingredients and store that in a separate container. The next day, just coat the beef, combine everything in the slow cooker, and turn it on!
Leftover Ideas
Leftover Mongolian Beef is fantastic! It makes a wonderful quick lunch over rice. You can also use it to make amazing fusion tacos with a bit of slaw, or chop it up and mix it into fried rice. The flavors almost seem to deepen overnight, making it a real treat.
Cooking Timeline
0-15 min: Slice the flank steak and coat it with cornstarch.
15-20 min: Whisk together all the sauce ingredients.
20 min - 4 hours: Combine beef and sauce in the slow cooker and cook on low.
4 hours - 4 hours 10 min: Remove the liquid, thicken it on the stovetop with a cornstarch slurry.
4 hours 10 min - 4 hours 20 min: Pour the thickened sauce back over the beef, stir in green onions, and serve.
Equipment & Shopping
Equipment You'll Need:
- •A 6-quart slow cooker is ideal for this recipe, as it allows the beef to spread out in a single layer and cook evenly in the sauce.
- •If you have a multicooker with a slow cook function, that works perfectly as well. You can even use its 'sauté' function to thicken the sauce at the end.
- •Using a slow cooker liner can make cleanup practically effortless, which is always a bonus on a busy weeknight.
Shopping List:
- •Flank steak
- •Cornstarch
- •Low-sodium soy sauce
- •Brown sugar
- •Fresh garlic
- •Fresh ginger
- •Green onions
- •Sesame oil
Ingredient Prep Guide
For the thinnest slices, make sure your knife is very sharp. A dull knife can tear the meat rather than slicing it cleanly.
Use a microplane or fine grater for the ginger and a garlic press for the garlic to ensure they melt seamlessly into the sauce without any chunky bits.
Slice your green onions on a slight diagonal for a more beautiful, professional-looking garnish.
Temperature Guide
Stovetop: Medium-high to bring the sauce to a boil for thickening
Oven: Not required for this recipe
Safe Internal Temp: Beef is cooked well-done in this recipe, far exceeding standard safety temperatures.
Perfect Pairings
Steamed jasmine or basmati rice
Quick-pickled cucumber salad
Roasted or steamed broccoli and carrots
Lo mein noodles or rice noodles
Pro Tips & Mistakes to Avoid
Common Mistakes to Avoid:
- •Slicing the beef with the grain instead of against it. This is the number one reason for tough beef, so always look for the direction of the muscle fibers and cut across them.
- •Forgetting to make a slurry. Don't add cornstarch directly to the hot liquid, as it will clump. Always dissolve it in cold water first before whisking it in.
- •Using regular soy sauce. The sauce will reduce over the long cooking time, and using full-sodium soy sauce can result in a final dish that is far too salty.
Flavor Boosters:
- •A splash of rice vinegar stirred in at the end can brighten up all the flavors and cut through the richness of the sauce.
- •For a deeper flavor, use half beef broth and half water as the liquid base for your sauce.
- •Toasting your sesame seeds in a dry pan for a minute before garnishing will make their nutty flavor and aroma much more pronounced.
Serving Suggestions
Serve over fluffy jasmine rice to soak up the savory sauce.
For a change of pace, try it over wide lo mein noodles or even simple spaghetti. My family loves it similarly to this beef and noodles dish.
For a lower-carb option, this is absolutely delicious served over cauliflower rice or with a side of roasted asparagus.
Garnish with sliced green onions and toasted sesame seeds for a fresh finish and a bit of crunch.
Chef's Special Notes
This dish is a fantastic alternative to takeout. It has all the flavor you crave but is made with simple, wholesome ingredients you control.
I sometimes like to make a double batch of the sauce. I'll use half for the recipe and freeze the other half. It's great to have on hand for a quick stir-fry.
Feel free to check out my General Tso's Chicken or Sweet Chili Chicken if you're looking for other easy, takeout-style slow cooker meals!
Recipe Variations
Spicy Mongolian Beef: For those who like a little kick, add 1-2 teaspoons of sriracha or a generous pinch of red pepper flakes to the sauce before cooking. It adds a lovely layer of warmth.
Mongolian Beef and Broccoli: Stir in 2 cups of fresh broccoli florets during the last 30 minutes of cooking on low, or simply steam them separately and mix in before serving to keep them bright and crisp.
Substitutions & Dietary Adaptations
Ingredient Substitutions:
- •Flank Steak → Sirloin Steak (Sirloin is another great option that will yield tender results. Slice it thinly against the grain just as you would with flank steak.)
- •Soy Sauce → Tamari or Coconut Aminos (To make this gluten-free, tamari is a perfect substitute. Coconut aminos also work well but are slightly sweeter, so you may want to reduce the brown sugar just a bit.)
Dietary Adaptations:
- •Gluten-Free: Use certified gluten-free tamari or coconut aminos instead of soy sauce. Ensure your beef broth is also labeled gluten-free.
- •Lower Sugar: You can reduce the brown sugar to 1/2 or 3/4 cup for a more savory sauce. You could also experiment with a brown sugar alternative if you prefer.
Slow Cooker Mongolian Beef: Easy Recipe
Easy slow cooker Mongolian beef recipe for a delicious weeknight dinner. Tender beef in a rich, savory sauce.
Timing
Prep Time
20 Minutes
Cook Time
4-6 Hours
Total Time
4 Hours 20 Minutes
Recipe Details
Ingredients
For the Beef
- 012 lbs flank steak, thinly sliced against the grain
- 021/2 cup cornstarch
- 032 tablespoons olive oil or vegetable oil
For the Mongolian Sauce
- 011 cup low-sodium soy sauce
- 021 cup water
- 031 cup packed brown sugar
- 044 cloves garlic, minced
- 051 tablespoon fresh ginger, grated
- 061 teaspoon sesame oil
- 071 cup sliced green onions, plus more for garnish
- 082 tablespoons cornstarch mixed with 4 tablespoons cold water (for slurry)
Instructions
Begin by preparing your beef. Take your thinly sliced flank steak and place it in a medium bowl. Sprinkle the 1/2 cup of cornstarch over the beef and toss it gently with your hands or a pair of tongs until every piece is lightly and evenly coated. This step feels a little like dusting with flour for baking, a quiet, tactile moment. This simple coating is what will give the beef a velvety texture and help thicken our sauce later on.
In a separate bowl, it’s time to create that magical sauce. Whisk together the low-sodium soy sauce, water, brown sugar, minced garlic, grated ginger, and sesame oil. Keep whisking until the brown sugar is mostly dissolved. The aroma that rises from the bowl at this point is just incredible—it’s the first promise of the deliciousness to come. It’s recipes like this that make a simple weeknight dinner feel so special.
Now, let’s bring it all together. Place the cornstarch-coated beef in the bottom of your slow cooker, spreading it out a bit. Pour the sauce mixture evenly over the beef. There’s no need to stir it vigorously, just enough to make sure the beef is submerged. Secure the lid, set your slow cooker to 'Low' for 4-6 hours or 'High' for 2-3 hours. Now, you can walk away and let the slow cooker work its quiet magic.
Once the cooking time is complete, the beef will be incredibly tender. Carefully transfer the cooking liquid from the slow cooker to a small saucepan on the stove over medium-high heat. In a small cup, mix the 2 tablespoons of cornstarch with the 4 tablespoons of cold water to create a slurry. Whisk this slurry into the saucepan and bring the sauce to a gentle boil. Let it simmer for 2-3 minutes, stirring constantly, until it has thickened into a beautiful, glossy glaze.
Pour the thickened sauce back over the beef in the slow cooker. Add the sliced green onions and gently stir everything together to coat. Let it sit for a few minutes to allow the flavors to meld. Serve this beautiful Mongolian Beef hot over a bed of fluffy rice or noodles, garnished with a few extra green onions and sesame seeds. It's pure comfort in a bowl.
Notes & Tips
- 1For an extra layer of flavor, you can sear the cornstarch-coated beef in a hot skillet with a bit of oil before adding it to the slow cooker. It’s an optional step but it adds a lovely depth and texture.
- 2The trick to slicing beef thinly is to partially freeze it first. About 20-30 minutes in the freezer firms it up perfectly, making it much easier to handle and slice with a sharp knife.
- 3Don't be tempted to use garlic powder or ground ginger. The fresh aromatics are truly the heart of this dish, and their vibrant flavor makes all the difference in the final sauce.
Tools You'll Need
- •6-Quart Slow Cooker: A standard 6-quart slow cooker is the perfect vessel for this recipe, giving the beef plenty of room to simmer without being overcrowded.
- •Sharp Chef's Knife: A good, sharp knife is essential for slicing the flank steak thinly and safely. It makes the prep work feel graceful and easy.
- •Mixing Bowls: You’ll want a couple of bowls on hand—one for coating the beef and another for whisking together that incredible sauce.
- •Small Saucepan: A small saucepan is needed at the very end to thicken the sauce on the stovetop, turning it into that perfect, glossy glaze.
Must-Know Tips
- 💡**Low and Slow is the Way:** For the most tender, melt-in-your-mouth beef, always opt for the 'Low' setting on your slow cooker if you have the time. Rushing it on high works, but low is where the magic really happens.
- 💡**Don't Add the Green Onions Too Early:** Wait to stir in the green onions until the very end. This keeps their color bright and gives them a pleasant, crisp-tender texture instead of becoming wilted.
- 💡**Taste the Sauce Before Thickening:** Give the cooking liquid a little taste before you move it to the saucepan. This is your chance to adjust if you think it needs a touch more sweetness or ginger.
Professional Secrets
- 🔥**A Touch of Sesame Oil at the End:** While some sesame oil goes into the initial sauce, adding just a tiny drizzle of toasted sesame oil right before serving awakens all the flavors and adds a beautiful, nutty aroma.
- 🔥**Slicing on a Bias:** When you slice the beef, cutting it at a slight angle (on a bias) increases the surface area of each slice, which helps it cook evenly and absorb more of the delicious sauce.
- 🔥**Let It Rest for a Moment:** After you stir the thickened sauce back in, let the dish rest in the warm slow cooker for about 5-10 minutes with the lid on. This allows the beef to soak up that glossy sauce completely.
Serving Suggestion
My favorite way to serve this is piled high on a bed of fluffy, steaming jasmine rice. The rice is just perfect for soaking up every last drop of that rich, savory sauce. A side of simple steamed broccoli or bok choy, still bright green and crisp, adds a wonderful freshness and a bit of color to the plate. I always garnish with a generous sprinkle of thinly sliced green onions and a scattering of toasted sesame seeds for a little texture and nutty flavor. It turns a simple slow cooker meal into something that feels elegant and thoughtfully composed.
Storage Instructions
If you have any leftovers, they are just as wonderful the next day. Allow the Mongolian Beef to cool completely before transferring it to an airtight container. It will keep beautifully in the refrigerator for up to 4 days. To reheat, you can gently warm it in a saucepan over low heat, adding a splash of water or beef broth to loosen the sauce if needed. You can also microwave it, but I find the stovetop method preserves the texture of the beef better. I wouldn’t recommend freezing this dish, as the texture of the beef can change upon thawing.
Allergy Information
This recipe contains soy and wheat (from the soy sauce) and sesame. To make this dish gluten-free, please be sure to use a certified gluten-free tamari or coconut aminos in place of the soy sauce. Always check the labels on all your ingredients, like beef broth, to ensure they are free from any potential allergens you need to avoid. This kitchen handles a variety of ingredients, so please be mindful if you have severe allergies.
The nutritional information provided here is an estimate and is not intended as medical advice. The values can vary based on the specific brands of ingredients used, the exact measurements, and the final serving size. For precise nutritional guidance, I recommend consulting with a registered dietitian or healthcare professional who can tailor advice to your specific dietary needs.
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