Slow Cooker Beef Stir Fry

Beef stir fry with bell peppers and onions being scooped from the slow cooker with a wooden spoon.

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Slow Cooker Beef Stir Fry

This slow cooker beef stir fry is made with tender flank steak, bell peppers, and onions cooked in a savory homemade sesame-soy sauce. It’s an easy, flavorful dinner that’s perfect served over rice.

Prep Time10

Cook Time4

Total Time4 10

Course: Dinner

Cuisine: Asian

Keyword: slow cooker beef stir fry

Servings:

Author: Katerina Petrovska

Equipment

Slow Cooker

Ingredients

1 tablespoon vegetable oil or canola oil
1½ to 2 pounds flank steak
salt and freshly ground black pepper to taste
1 large yellow onion sliced
3 cloves garlic minced
1 teaspoon freshly grated ginger or ½ teaspoon ground ginger
¼ cup low sodium beef broth or water
½ cup low-sodium soy sauce
¼ cup honey or packed brown sugar
2 tablespoons rice vinegar
1 tablespoon toasted sesame oil
2 bell peppers any color, cut into strips
1 tablespoon cornstarch
1 tablespoon cold water
sliced green onions and sesame seeds for garnish, optional

Instructions

Sear the beef. Season the flank steak with black pepper and a little salt. Heat 1 tablespoon of cooking oil in a large skillet over medium-high heat. Sear the steak for 1 to 2 minutes per side, just until browned. Transfer it to the slow cooker.
Add the onion and garlic. In the same skillet, cook the onion, garlic, and ginger for 1 minute. Pour in the beef broth and scrape up the browned bits from the bottom of the skillet. Transfer everything to the slow cooker, spooning it around and over the steak.
Make the sauce. Whisk together the soy sauce, honey, rice vinegar, and sesame oil. Pour the sauce over the beef.
Slow cook. Cover and cook on LOW for 4 to 5 hours or on HIGH for 2½ to 3 hours, until the flank steak is tender.
Add the peppers. Add the sliced bell peppers during the last 45 to 60 minutes of cooking so they become tender without getting overly soft.
Slice the beef. When cooked, transfer the flank steak to a cutting board and let it rest for about 5 minutes. Thinly slice the steak against the grain, then return it to the slow cooker.
Thicken the sauce. Whisk the cornstarch with 1 tablespoon of cold water until smooth. Stir the slurry into the slow cooker. Cover and cook on HIGH for another 10 to 15 minutes, or until the sauce has thickened.
Serve. Stir everything together and serve over rice or quinoa, garnished with green onions and sesame seeds.

Notes

Adjust the sauce. The beef and vegetables will release liquid as they cook. If you'd like more sauce at the end, stir in a splash of water or low-sodium beef broth before adding the cornstarch slurry.
Don't overcook the beef. Flank steak is lean, so start checking it at the earlier end of the cooking range. The beef is ready when it's tender and slices easily; cooking it much longer can make it dry and stringy.
Slice against the grain. Flank steak can be chewy if it's sliced with the grain. Look for the long muscle fibers and cut across them into thin strips.

Nutrition