Slow Cooker Mongolian Beef Recipe – Sticky Sweet Sauce

Slow Cooker Mongolian Beef features tender slices of flank steak simmered in a glossy sweet-and-savory sauce made from garlic, ginger, brown sugar, and soy sauce. This easy slow cooker version captures the bold flavors you expect from a favorite Chinese restaurant dish but requires minimal hands-on time — ideal for busy weeknights when you want a comforting, family-friendly dinner without the takeout.

If you enjoy quick Mongolian-style dinners like my 15-minute Mongolian ground beef and noodles, this slow cooker version delivers many of the same flavors with a “set it and forget it” approach. The slow heat breaks down the flank steak so it becomes extra tender while the sauce thickens and coats each piece with a rich, caramelized glaze.

Why I love this recipe

• Minimal prep: about 5 minutes to slice and combine ingredients, which makes it perfect for hectic afternoons.
• Hands-off cooking: the slow cooker tenderizes the beef and melds flavors while you take care of other tasks.
• Family favorite: the sweet-savory sauce is broadly appealing and often earns rave reviews at dinner time.

Ingredients

A few simple pantry staples are all you need for this Crockpot Mongolian Beef.

• Flank steak — sliced thinly against the grain. You can substitute thin sirloin or skirt steak; avoid stew meat for best texture.
• Cornstarch
• Toasted sesame oil
• Minced garlic
• Ground ginger (or fresh minced ginger)
• Soy sauce
• Brown sugar (light or dark)
• Beef broth
• Green onions for garnish

Step by step

Follow these straightforward steps for reliable results.

1. Slice the flank steak into thin strips, cutting across the grain to keep bites tender.
2. Toss the sliced beef with the cornstarch in a bowl or a sealed plastic bag so each piece is lightly coated.
3. Place the coated steak in the slow cooker and add the toasted sesame oil, garlic, ginger, soy sauce, brown sugar, and beef broth. Reserve the green onions for the end.
4. Stir well so the meat is evenly coated with the sauce.
5. Cook on high for 2–3 hours or on low for 4–5 hours, until the beef is tender and the sauce has thickened slightly.
6. Stir in most of the sliced green onions just before serving and sprinkle extra on top as a fresh garnish.

Variations

This recipe is flexible — try one of these simple variations to customize the dish:

• Add vegetables such as shredded carrots, bell peppers, green beans, peas, or mixed vegetables during the last hour of cooking so they stay crisp-tender and soak up the sauce.
• For heat, stir in red pepper flakes or a splash of chili paste to taste.
• Use an Instant Pot: brown the meat on Sauté, add the sauce ingredients, then pressure cook on high for 10 minutes and quick-release.
• Finish with toasted sesame seeds for added crunch and aroma.

Serving suggestions

Serve this Mongolian beef over steamed white rice, brown rice, fried rice, or cauliflower rice. Toss it with lo mein noodles or even spaghetti if you’re in a pinch. Simple vegetable sides like sautéed broccoli or sautéed green beans complement the rich sauce and round out the meal.

Storage

Store: Keep leftovers in an airtight container in the refrigerator for up to 3 days.

Freeze: Freeze cooled leftovers in a freezer-safe container or bag for up to 3 months. Thaw overnight in the refrigerator before reheating.

Reheat: Gently warm portions in the microwave or on the stovetop until heated through. If the sauce has thickened too much after chilling, add a splash of water or broth while reheating to loosen it.

Recipe details

• Author: Melissa Riker
• Total Time: about 3 hours 5 minutes (includes cook time)
• Prep Time: 5 minutes
• Cook Time: 3 hours (approximate; high 2–3 hours, low 4–5 hours)
• Yield: Serves about 5
• Method: Slow cooker
• Cuisine: Chinese-inspired

Ingredients (actual amounts)

• 1 1/2 pounds flank steak
• 1/4 cup cornstarch
• 2 teaspoons toasted sesame oil
• 1 teaspoon minced garlic
• 1/2 teaspoon ground ginger
• 1/2 cup soy sauce
• 1/3 cup brown sugar
• 1/2 cup beef broth
• Green onion, sliced, for garnish

Instructions (concise)

1. Slice steak thin against the grain and toss with cornstarch to coat.
2. Combine steak and remaining ingredients (except green onions) in the slow cooker and stir to coat.
3. Cook on high 2–3 hours or low 4–5 hours, until beef is tender and sauce is glossy.
4. Stir in green onions and serve over rice or noodles.

Nutrition

• Calories: 301 per serving
• Sugar: 14.3 g
• Sodium: 796.3 mg
• Fat: 8.7 g
• Carbohydrates: 22.6 g
• Protein: 31.4 g

If you make this Slow Cooker Mongolian Beef, please leave a comment and rating — feedback helps refine the recipe and inspires others to try it. Enjoy a flavorful, low-effort dinner that’s sure to become a regular in your weeknight rotation.