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Slow Cooker Mongolian Beef is an easy and delicious fake out-take out meal you can make at home with just a few minutes of prep work! It’s the perfect slow cooker meal that hits all the sweet and savory cravings.

A bowl of rice topped with sliced slow cooker mongolian beef, shredded carrots, cucumbers, and green onions sits next to a Crockpot filled with more beef. A fork rests in the bowl and sesame seeds are sprinkled on top.


 

👩‍🍳 Everything you need is probably already in your kitchen! Basic ingredients like soy sauce, brown sugar, and sesame oil come together to create complex, restaurant-quality flavors.

Table of Contents

My 2 Best Tips For Making Slow Cooker Mongolian Beef

Slicing Against the Grain: This is absolutely crucial for tender bites! Look for the natural lines in your flank steak and slice perpendicular to them. For easier slicing, pop the flank steak in the freezer for 20–30 minutes before cutting – it firms up just enough to make clean cuts.

Balance Sweet and Salty: The brown sugar perfectly balances the salty soy sauce, but feel free to adjust to your taste. For a less sweet version, reduce to ⅓ cup; for a richer flavor, try dark brown sugar instead of light.

    Melissa in her kitchen smiling in front of the starting ingredients for the chicken the quinoa salad and skillet chicken on the wood block in front of her

    🩷 Melissa

    This slow cooker Mongolian beef has become such a staple in our house that I keep all the ingredients stocked in my pantry.

    It’s proof that you don’t need complicated techniques or exotic ingredients to create something truly special – sometimes the best meals are the simplest ones that bring your family together around the dinner table.

    This dish reheats beautifully and tastes even better the next day as the flavors continue to blend. Make a big batch on Sunday and enjoy easy lunches all week long!

    A bowl of white rice topped with sliced beef, julienned carrots, cucumber salad, and green onions sits next to a Crockpot, with a fork resting in the bowl.
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    Slow Cooker Mongolian Beef

    By: Melissa Griffiths
    Slow Cooker Mongolian Beef is an easy and delicious fake out-take out meal you can make at home with just a few minutes of prep work! It's the perfect slow cooker meal that hits all the sweet and savory cravings.
    Prep: 20 minutes
    Cook: 4 hours
    Total: 4 hours 20 minutes
    Servings: 6
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    Ingredients 

    • 1 ½ pounds flank steak
    • 2 teaspoons sesame oil
    • 2 cloves garlic, minced
    • 1 teaspoon freshly grated ginger
    • ½ cup soy sauce
    • ½ cup beef broth
    • ¾ cup water
    • ½ cup brown sugar, packed
    • ¼ cup cornstarch
    • 5 green onions, chopped, green and white parts separated
    • Cooked rice, for serving

    Instructions 

    • Thinly slice the flank steak against the grain. You don't want them too thin here though or they'll fall apart in the slow cooker. Shoot for about ½-inch slices. Place in the bottom of the slow cooker.
    • In a small bowl, combine the sesame oil, garlic, ginger, soy sauce beef broth, water, brown sugar, and corn starch. Use a fork to combine the ingredients well and then pour them over the meat in the slow cooker.
    • Chop the green onions and divide the green parts from the white parts. Put all of the chopped white parts in the slow cooker. Reserve the greens for serving.
    • Cover and cook on low for 4–6 hours, until the beef is tender and the sauce has thickened.
    • Serve hot over cooked rice. Garnish with green parts of onions.

    Notes

    Slow Cooker Size: 6-quart
    Recipe Variations & Substitutions:
    • The brown sugar balances the salty soy sauce. For a less sweet version, reduce to ⅓ cup; for a richer flavor, try dark brown sugar.
    • Add red pepper flakes or add a drizzle of sriracha before serving for more heat.
    • Use low-sodium soy sauce to better control the saltiness.
    • Serve over rice, but it’s also great with noodles or even inside lettuce wraps for a lighter option.
    • You can swap out the beef broth for chicken if that’s what you have on hand. 
    Slicing Trick: Cutting against the grain into thin strips is key to tender bites. For easier slicing, pop the flank steak in the freezer for 20–30 minutes before cutting.
    Storing Leftovers: This dish reheats really well! Store leftovers in an airtight container in the fridge for up to 4 days or freeze for up to 2 months.

    Nutrition

    Serving: 1 of 6 servings, Calories: 275kcal, Carbohydrates: 25g, Protein: 27g, Fat: 7g, Saturated Fat: 3g, Polyunsaturated Fat: 1g, Monounsaturated Fat: 3g, Cholesterol: 68mg, Sodium: 1223mg, Potassium: 496mg, Fiber: 0.5g, Sugar: 18g, Vitamin A: 100IU, Vitamin C: 2mg, Calcium: 54mg, Iron: 3mg
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    How to Make Mongolian Beef in the Slow Cooker

    A wooden board with sliced green onions, chopped garlic, a bowl of sliced raw beef, soy sauce, cornstarch, and a small bowl of chopped dried chili peppers arranged for cooking.

    Step 1: Thinly slice the flank steak against the grain. Shoot for about ½-inch slices. Place in the bottom of the slow cooker.

    Strips of raw beef, chopped green onions, and seasonings in broth inside a black slow cooker, placed on a countertop.

    Step 2: Combine the sesame oil, garlic, ginger, soy sauce beef broth, water, brown sugar, and corn starch. Pour over the meat in the slow cooker and add the white parts of the chopped onions.

    Sliced beef and mushrooms in a rich brown sauce inside a black slow cooker, with a silver spoon resting in the mixture.

    Step 3: Cover and cook on low for 4–6 hours, until the beef is tender and the sauce has thickened.

    Two bowls of rice topped with beef, sliced cucumbers, carrots, and green onions sit next to a bowl of extra rice, a bowl of sliced cucumbers, and a slow cooker filled with beef in sauce. Spoons and forks are placed nearby.

    Step 4: Serve hot over cooked rice. Garnish with green parts of onions.

    Recipe FAQs

    Can I use a different cut of beef instead of flank steak?

    Yes! Chuck roast or beef stew meat work wonderfully in this recipe. They’ll become incredibly tender during the long cooking process. Just adjust your slicing technique accordingly – chuck roast can be cut into larger chunks since it breaks down more than flank steak.

    How do I make this recipe gluten-free?

    For gluten-free, simply substitute the soy sauce with tamari or coconut aminos, and use cornstarch (which you’re already using) instead of flour for thickening.

    My sauce didn’t thicken properly. What went wrong?

    This usually happens when the cornstarch wasn’t mixed in completely or if there’s too much liquid. Next time, make a slurry by mixing the cornstarch with a small amount of cold water before adding to prevent clumps. If your sauce is thin, mix 1 tablespoon cornstarch with 2 tablespoons cold water and stir it in during the last 30 minutes of cooking.

    A bowl of white rice topped with shredded beef, sliced green onions, sesame seeds, julienned carrots, and cucumber, with a fork. A crockpot and another bowl of food are in the background.

    More Savory Beef Recipes To Try

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