Ultimate Slow Cooker Mongolian Beef (Printable Version)

Tender beef in a rich garlic-ginger sauce, slow cooked for deep, savory flavor and perfect texture.

# What You'll Need:

→ Beef

01 - 2 pounds flank steak, thinly sliced against the grain

→ Sauce

02 - 3/4 cup low-sodium soy sauce
03 - 1/2 cup dark brown sugar, packed
04 - 1/2 cup water
05 - 1/4 cup hoisin sauce
06 - 1 tablespoon sesame oil
07 - 1 tablespoon freshly grated ginger
08 - 5 cloves garlic, minced
09 - 1/2 teaspoon freshly ground black pepper
10 - 1/4 teaspoon crushed red pepper flakes

→ Thickener

11 - 1/4 cup cornstarch

→ Vegetables & Garnish

12 - 5 green onions, sliced (white and green parts separated)
13 - 1 tablespoon toasted sesame seeds
14 - Steamed white or brown rice, for serving

# How to Make It:

01 - Toss sliced flank steak with cornstarch in a large bowl until evenly coated. Shake off excess powder before transferring to slow cooker.
02 - Whisk together soy sauce, brown sugar, water, hoisin sauce, sesame oil, ginger, garlic, black pepper, and red pepper flakes in a separate bowl until sugar dissolves completely.
03 - Place cornstarch-coated beef in the slow cooker. Pour sauce mixture over the meat and toss gently to coat evenly. Scatter white parts of green onions across the top.
04 - Cover and cook on low heat for 4 hours until beef becomes tender and sauce thickens slightly. Avoid opening lid during cooking to maintain consistent temperature.
05 - Stir in green onion tops and cook for 10 additional minutes. Serve immediately over steamed rice, garnished with toasted sesame seeds and extra green onions if desired.

# Expert Insights:

01 -
  • The beef becomes impossibly tender, almost melting in your mouth
  • That sauce clings to every single bite like magic
  • Four hours of hands-off cooking instead of twenty minutes of active stress
02 -
  • Against the grain slicing is non-negotiable for tender flank steak
  • Do not skip the cornstarch coating, it completely changes the texture
  • The sauce will look thin at first but thickens beautifully during cooking
03 -
  • Slice the beef while partially frozen for easier, thinner cuts
  • Use tamari instead of soy sauce for a gluten-free version
  • The red pepper flakes are optional but I highly recommend them for depth

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