Ultimate Slow Cooker Mongolian Beef (Printable)

Silky tender beef in rich Asian-inspired sauce, ready in your slow cooker.

# 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

# Step-by-step:

01 - Toss the sliced flank steak with cornstarch in a large bowl until all pieces are evenly coated. Shake off any excess cornstarch before adding to the slow cooker.
02 - Add the cornstarch-coated beef to the slow cooker insert, spreading pieces in an even layer.
03 - Whisk together soy sauce, brown sugar, water, hoisin sauce, sesame oil, freshly grated ginger, minced garlic, black pepper, and crushed red pepper flakes in a separate bowl until sugar is completely dissolved.
04 - Pour the prepared sauce over the beef in the slow cooker. Gently toss to coat all pieces evenly with the sauce mixture.
05 - Scatter the white parts of the sliced green onions over the top of the beef and sauce mixture.
06 - Cover and cook on low heat for 4 hours, or until the beef is fork-tender and the sauce has thickened slightly. Avoid opening the lid frequently to maintain consistent temperature.
07 - Stir in the sliced green onion tops and cook for an additional 10 minutes until the green parts are wilted but still vibrant.
08 - Serve hot over steamed white or brown rice. Garnish with toasted sesame seeds and additional green onions if desired.

# Expert Advice:

01 -
  • The beef becomes impossibly tender, like something you'd order at a restaurant but better because your house smells amazing all day
  • The sauce strikes that perfect balance between savory and sweet that makes everyone reach for seconds
  • Almost zero active cooking time, just whisk and walk away until dinner
02 -
  • The sauce might look thin when you first pour it in, but it thickens beautifully as the cornstarch from the beef cooks into the liquid
  • Every slow cooker runs differently, so start checking at 3.5 hours if your appliance runs hot
  • That cornstarch coating is what gives the beef that restaurant-style velvety texture, so don't skip it
03 -
  • Partially freeze the flank steak for 30 minutes before slicing, which makes cutting those thin, even slices so much easier
  • Use a box grater for the ginger instead of mincing it to get those tiny bursts of intense flavor throughout the sauce

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