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Tender pieces of flank steak are slow-cooked in the tastiest sweet and savory sauce. This slow cooker Mongolian beef is melt-in-your-mouth perfection and bursting with flavor. Quick and easy to prepare and one of our favorite slow cooker meals!
If you love restaurant Mongolian Beef, this super easy make-at-home rendition will be your new favorite dinner. Serve over this easy fried rice for a complete meal. And if you really want to wow your guests, egg rolls and vegetable stir-fry on the side would be amazing!

Slow Cooker Mongolian Beef
Mongolian beef made in the slow cooker is life-changing! Slow cooking the beef ensures that it’ll be delicate and succulent. This slow cooker Mongolian beef recipe is an explosion of flavors in every bite! Garlic, soy sauce, and brown sugar come together to create a caramelized sauce that coats the tender juicy pieces of steak. Just like in my slow cooker beef and broccoli.
This is hands down one of the BEST dinners that I have ever made. My family couldn’t get enough of it! It’s so easy to make restaurant-worthy meals for the family at home. If you love this slow cooker Mongolian beef recipe then I can’t wait for you to try more of our favorites. Make this sweet and sour chicken, these lettuce wraps, of this incredible bang bang chicken.
Mongolian Beef Ingredients
Slow cooker Mongolian beef is SO easy to make with minimal ingredients. The ingredients are simple, but the outcome is incredible! Your dinner is prepped and ready to go in under 10 minutes! If you are looking for another slow cooked beef meal, try my Slow Cooker Beef Tips next!
- Flank Steak: Sirloin can be substituted here but avoid stew meat.
- Corn Starch: This acts as a natural tenderizer for the beef.
- Olive Oil: Use canola oil if you’d rather.
- Garlic: Minced or chopped will give the most flavor.
- Soy Sauce: Either low-sodium soy sauce or coconut aminos can be used here.
- Water: This will help make it saucy.
- Brown Sugar: Light or dark brown sugar is both great in the sauce.
- Carrots: Grate a carrot or instead use pre-shredded carrots.
- Green Onions and Sesame Seeds: Optional garnish, but make a stunning topping.
How to Make Mongolian Beef in a Slow Cooker
The beef literally just melts in your mouth! You can always count on the slow cooker for tender beef. The tasty sauce clings to the cornstarch-coated steak and every bite is bursting with flavor. See the recipe card below for exact measurements.
- Cut and Coat: Cut the flank steak thinly and across the grain to ensure a tender bite. Place the steak in a ziplock bag with the cornstarch then shake to coat. Make sure to coat the beef evenly.
- Add ingredients to the Slow Cooker: Mix the oil, garlic, soy sauce, water, brown sugar, and carrots in the slow cooker.
- Coat the Beef: Stir the beef into the slow cooker making sure it’s well-coated
- Cook: Set on high for 2-3 hours or on low for 4-6 hours.
- Garnish and Enjoy: Garnish with chopped green onion and sesame seeds for added flavor and texture then enjoy over rice!

Tips and Variations
Everything about this Mongolian recipe is perfect, and I know that it will become a family favorite at your house just like it did at ours! Here are some ideas and variations to make it your own! I also included instructions for making it in the instant pot when you’re short on time!
- Slicing the Beef: When slicing the flank steak make sure to slice it against the grain. I like to slice mine about 1/4 inch thick.
- Veggies: Roast broccoli, green beans or red bell pepper then stir in before serving. Vegetables add texture and nutrition.
- Instant Pot: This easily converts to a quick Instant Pot recipe. Saute the steak on high until browned. Add the sauce ingredients and cook on “Manual” for 10 minutes. Lastly, quick release the pressure and enjoy!

How to Store Leftovers
Store any leftover Mongolian beef you may have, because it’s great for heating up and enjoying later! I like to make a little extra rice as well for a quick lunch that’s super satisfying!
- In the Refrigerator: Place leftovers in a sealed container for up to 4 days.
- In the Freezer: Once cooled, store leftovers in an air-tight container or freezer ziplock bag for up to 4 months. Thaw in the refrigerator before rewarming.
- To Reheat: Place leftovers in a microwave-safe bowl then heat for 1-2 minutes or until warmed through.

More Savory Slow Cooker Recipes
Slow cooker dinners always save the day! They’re easy and SO delicious. Everyone loves coming home to a warm home-cooked dinner. Try some of our favorites this week for dinner. You’ll love them all!
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Slow Cooker Mongolian Beef
Ingredients
- 1 ½ pounds flank steak
- ¼ cup cornstarch
- 2 tablespoons olive oil
- 1 teaspoon garlic, minced
- ¾ cup soy sauce
- ¾ cup water
- ¾ cup brown sugar
- 1 cup carrots, grated
- green onions and sesame seeds, for garnish
Instructions
- Cut 1 ½ pounds flank steak into thin strips. In a ziplock bag, add flank steak pieces and ¼ cup cornstarch. Shake to coat.
- In a medium-sized bowl, add 2 tablespoons olive oil, 1 teaspoon garlic, ¾ cup soy sauce, ¾ cup water, and ¾ cup brown sugar. Whisk to combine and add to the slow cooker.
- Add 1 cup carrots, and coated flank steak to the slow cooker and stir until coated in the sauce.
- Serve over rice and garnish with green onions and sesame seeds,.
Video
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.


















Could the Mongolian beef be made ahead of time, frozen, then defrosted, and rewarmed to mix with other casseroles to serve for Xmas Eve and can you recommend other 5 star recipes that could be made ahead of time, frozen, then defrosted and either cooked or rewarmed for Xmas Eve by either using a crockpot and or throwaway foil lasagna pan? I’m trying to make some main dishes ahead of time since I work full time, and my husband and I are hosting Xmas Eve this year with about 15 guests. I have a plug in warming tray that accommodates 4 lasagna sized pans and 2 crockpots to keep food warm. This way we can enjoy our company without being stuck in the kitchen.
Absolutely! The Mongolian beef can be made ahead, frozen, thawed overnight in the fridge, and reheated. I’d keep it warm in one of your crockpots.
For a few other make-ahead options, I’d recommend:
Pesto Alfredo Chicken Casserole: Freezes well and can be thawed overnight before baking.
Hobo Casserole: Cook, freeze, thaw, and reheat right in a foil pan.
Lazy Meatball Lasagna: Assemble it ahead, freeze it, then thaw overnight or bake from frozen.
Your warming tray and crockpots sound perfect for keeping everything hot without being stuck in the kitchen all night!
Love this recipe! I used flat iron steak in my freezer so used that. Add a half of onion quartered no carrots. Also added some ginger and rice wine vinegar as I thought it was a bit sweet. Also a splash of sriracha. Served it with roasted broccoli and carrots and wild rice mix. So easy to throw together