Better Than Takeout: Just 5 ingredients. Put sliced steak in the slow cooker and let the sauce do the work. It comes out sticky, sweet, and savory without the delivery fee.
This 5-ingredient slow cooker Mongolian beef is my kind of weeknight magic: you literally slice the flank steak, toss it in the crockpot, whisk together a quick sauce, and walk away. Hours later you lift the lid to glossy, sticky, sweet-and-savory strips of beef that taste like your favorite takeout, but with almost no effort and no delivery fee. Mongolian beef isn’t actually from Mongolia—it’s a Chinese-American restaurant classic known for its caramelized soy-garlic sauce and tender beef, and this version leans into that flavor with a super-short ingredient list and a hands-off cooking method that fits right into a busy schedule.
Serve this slow cooker Mongolian beef over a big bowl of steamed white or brown rice so it can soak up all that sticky, dark amber sauce. I like to add a simple side of steamed or stir-fried veggies—broccoli, green beans, or a frozen stir-fry blend—to round out the plate without extra fuss. If you’re watching carbs, spoon the beef over cauliflower rice or shredded cabbage. A sprinkle of sliced green onions or sesame seeds on top makes it feel restaurant-worthy, even if you threw it together between work emails.
5-Ingredient Slow Cooker Mongolian Beef
Servings: 4
Ingredients
2 pounds flank steak, thinly sliced against the grain into strips 3/4 cup low-sodium soy sauce 3/4 cup packed brown sugar 1/2 cup beef broth (or water) 2 tablespoons minced garlic (about 6 cloves)
Directions
Slice the flank steak: Place the flank steak on a cutting board and slice it thinly against the grain into bite-size strips, about 1/4 inch thick. This helps the meat stay tender after slow cooking.
Add steak to slow cooker: Place all of the sliced flank steak into the bottom of a 4- to 6-quart slow cooker, spreading it out as evenly as you can so the sauce can coat every piece.
Make the sauce: In a medium bowl or large measuring cup, whisk together the low-sodium soy sauce, brown sugar, beef broth (or water), and minced garlic until the sugar is mostly dissolved and everything is well combined.
Combine steak and sauce: Pour the sauce evenly over the sliced steak in the slow cooker. Use tongs or a spoon to gently toss the beef so every strip is coated in the dark, glossy mixture.
Slow cook until tender: Cover the slow cooker with the lid and cook on LOW for 3 1/2 to 4 1/2 hours, or until the beef is very tender and the sauce has thickened into a sticky, caramelized glaze clinging to the meat. Avoid lifting the lid too often so the heat and moisture stay in.
Adjust and serve: Once the beef is done, give everything a gentle stir. The sauce should be dark amber, shiny, and thick enough to coat the back of a spoon. If it’s a bit thin, leave the lid off and cook on HIGH for 15 to 20 minutes to reduce and concentrate. Taste and add a splash of water or a pinch of extra brown sugar if needed to balance the saltiness. Serve hot over rice with your favorite veggies.
Variations & Tips
For a touch of heat, stir 1/2 to 1 teaspoon of crushed red pepper flakes into the sauce before pouring it over the beef. If you like a thicker, almost syrupy sauce, whisk 1 tablespoon of cornstarch into the cold beef broth before mixing it with the soy sauce and brown sugar; the sauce will tighten up more as it cooks and cools slightly. To keep it a true 5-ingredient recipe but add a little freshness at serving time, top the finished beef with sliced green onions or a sprinkle of toasted sesame seeds—both optional but highly recommended. If you don’t have beef broth, water works just fine; the soy sauce and brown sugar still create that rich, takeout-style flavor. For meal prep, cook a batch on Sunday, portion it with rice into containers, and refrigerate for up to 4 days; the sauce thickens even more in the fridge and reheats beautifully in the microwave or in a skillet with a splash of water. You can also halve the recipe for a smaller slow cooker or double it for a crowd—just keep the slices thin and avoid overfilling past the manufacturer’s guidelines so the sauce can still bubble and caramelize properly.
