Slow Cooker Mongolian Beef — Step-by-Step SEO-Optimized Recipe

A cozy, hands-off version of the popular takeout favorite — Slow Cooker Mongolian Beef gives you tender, flavor-packed slices of flank steak simmered in a sweet-savory soy-brown sugar glaze. It’s effortless: coat the beef, dump the sauce, and let the crockpot do the rest. Perfect over rice or noodles for a quick weeknight comfort meal.

 Recipe At a Glance

• Recipe name: Slow Cooker Mongolian Beef (Crockpot)

• Servings: 4 (adjust easily)

• Prep time: 10–15 minutes

• Cook time: 2–3 hours on HIGH or 4–5 hours on LOW

• Total time: 2–5 hours 15 minutes depending on setting

• Method: Slow cooker / crockpot

• Cuisine: Asian-inspired / Chinese takeout style

 Ingredients

• 1.5 pounds (about 680 g) thinly sliced flank steak — slice against the grain

• 1/4 cup cornstarch (for coating)

• 1 tablespoon toasted sesame oil

• 1 teaspoon finely chopped garlic (about 1 large clove)

• 1 teaspoon finely chopped fresh ginger

• 1/3 cup packed brown sugar

• 1/2 cup soy sauce

• 1/2 cup water

• Optional: 1/2 cup green onions, sliced (stir in last 30 minutes or use as garnish)

• For serving (suggestions): steamed white or brown rice, cauliflower rice, or lo mein noodles; sesame seeds for garnish

 Step-by-Step Instructions

1 — Slice the beef

Slice the flank steak thinly against the muscle fibers. Thin slices cook quickly and stay tender. Pat the slices dry with paper towels to remove excess moisture so the cornstarch sticks.

2 — Coat the beef

Place the sliced beef in a large bowl or a resealable bag. Add the 1/4 cup cornstarch and toss thoroughly until each piece is evenly coated. Shake off any large clumps of excess cornstarch.Why: The cornstarch creates a light coating that helps thicken the sauce and gives the beef a velvety texture.

3 — Layer aromatics in the slow cooker

Place the cornstarch-coated beef into the slow cooker. Add 1 tablespoon toasted sesame oil, 1 tsp minced garlic, and 1 tsp minced ginger — either mixed with the beef or scattered on top.

4 — Make the sauce

In a small bowl, whisk together:

• 1/3 cup brown sugar

• 1/2 cup soy sauce

• 1/2 cup water

Pour the sauce over the beef, making sure the beef is well coated and mostly submerged.

5 — Slow cook

Cover and cook:

• LOW: 4–5 hours, or

• HIGH: 2–3 hours.

Cook until the beef is fork-tender but not falling apart. Because the slices are thin, they will become very tender — check at the lower end of the time range to avoid overcooking.

6 — Finish with green onions (optional)

If using green onions, stir in 1/2 cup sliced green onions during the last 20–30 minutes of cooking so they remain vibrant and slightly crisp. Save some green onions for garnish.

7 — Thicken (if needed) & serve

If the sauce is thinner than you like, remove the lid and cook on HIGH for 10–15 minutes to reduce, or whisk together 1 tsp cornstarch + 1 tbsp cold water and stir into the hot sauce, cooking another 2–3 minutes until glossy and thickened.

Serve the Mongolian beef hot over steamed rice or noodles. Garnish with additional sliced green onions and sesame seeds if desired.

 Serving Suggestions

• Classic: Steamed jasmine rice + a side of steamed broccoli.

• Low-carb: Serve over cauliflower rice.

• Comfort combo: Spoon over buttery egg noodles with a sprinkle of toasted sesame seeds.

• Vegetables: Add snap peas, sliced bell pepper, or steamed bok choy during the last hour for extra color and texture.

Variations & Substitutions

• Chicken or pork: Use thinly sliced boneless, skinless chicken thighs or pork loin instead of beef (adjust cooking time — chicken cooks faster).

• Less sweet: Reduce brown sugar to 1/4 cup or swap with coconut sugar or maple syrup (use less maple, it’s sweeter).

• Gluten-free: Use tamari or a gluten-free soy sauce.

• Spicy kick: Add 1–2 tsp sriracha or 1/2 tsp red pepper flakes to the sauce.

• Crispy finish: For a takeout-style texture, remove cooked beef and quickly pan-fry in a hot skillet for 1–2 minutes to re-crisp edges before tossing in sauce.

 Pro Tips for Best Results

1. Slice against the grain — the single most important step for tender bites.

2. Don’t overcook. Thin slices become mushy if left too long; check at the earlier end of the cook time.

3. Toasted sesame oil adds a deeper, nuttier flavor than plain sesame oil — use if available.

4. Cornstarch coating is key: it both slightly seals the meat and helps thicken the final sauce.

5. Adjust saltiness after cooking — soy sauce levels vary widely; taste before adding extra salt.

 Storage & Reheating

• Fridge: Store leftovers in an airtight container for up to 3 days.

• Freezer: Freeze in portions for up to 2 months (thaw overnight in fridge).

• Reheat: Warm gently on the stove over medium heat, adding a splash of water if sauce has thickened or congealed; avoid high heat to prevent drying the meat.

 Estimated Nutrition (per serving — approximate, recipe makes 4 servings)

Calculated from the ingredient portions above and rounded for clarity.

• Calories: ~566 kcal per serving

• Protein: ~44.2 g per serving

• Fat: ~28.9 g per serving

• Carbohydrates: ~25.2 g per serving

• Sodium: ~1,740 mg per serving

• Note: Nutrition values are estimates only. Actual values depend on the exact cut of beef, brand of soy sauce, amount of oil absorbed, and serving size. Soy sauce contributes most of the sodium — use low-sodium soy sauce to significantly reduce salt.

enjoy!