Go Back
+ servings
Crockpot Mongolian Beef recipe

Slow Cooker Mongolian Beef

Have this tasty Mongolian Beef ready when you get home from work, thanks to your crockpot! Salty, a little sweet and a touch of heat make this the perfect at-home version of take out.
Prep Time 10 minutes
Cook Time 6 hours
Total Time 6 hours 10 minutes
Servings 4
Author Jacqueline


  • 2/3 cup soy sauce
  • 1/3 cup water
  • 1/2 cup brown sugar
  • 2 teaspoons crushed red pepper flakes
  • 2 teaspoons rice vinegar
  • 4 cloves minced garlic
  • 1 tablespoon fresh grated ginger
  • 1 large onion sliced 1/2"
  • 1.5 lbs flank steak
  • 2 tablespoons cornstarch
  • 3 green onions dark and light green parts sliced 1/4"


  • In a small bowl, whisk together soy sauce, water, brown sugar, red pepper, vinegar, garlic, and ginger.
  • Slice the flank steak against the grain into 1/2" strips and place in slow cooker. Add onions, toss to combine. Pour sauce over top. 
  • Cover and cook on LOW 6 hours or HIGH for 3-4. 
  • At the end of cooking, you have two options- remove a small amount of cooking liquid and whisk it into the cornstarch in a separate small bowl until smooth, then return it to the slow cooker, stir in and cook on HIGH for 45 minutes to thicken the sauce; or, pour off all cooking liquid into a saucepan, whisk in the cornstarch and simmer on the stove until thickened.
  • Gently stir together the beef and onions, sauce and green onions. Serve over white rice.