Mongolian Beef Recipe

Slice beef

Place the flank steak in the freezer for 15–20 minutes to firm it up. Using a sharp knife, slice across the grain into very thin strips about 1/8–1/4 inch thick.

Marinate

In a bowl toss the beef strips with 1 tablespoon soy sauce, 1/2 teaspoon baking soda, 1/4 teaspoon salt, and 1/4 teaspoon black pepper. Let sit 10–15 minutes. The baking soda will help tenderize the meat.

Coat with cornstarch

After marinating, add 1/2 cup cornstarch to the beef and toss until each piece is lightly coated. Shake off excess cornstarch and set the strips on a tray while you heat oil.

Shallow fry or pan-fry beef

Heat 1/4 cup neutral oil in a large heavy skillet or wok over medium-high heat until shimmering (about 375°F if using a thermometer). Fry the coated beef in batches so pieces are not crowded, 1–2 minutes per side, until crisp and browned. Transfer to a wire rack or paper towel-lined plate to drain. Reserve.

Combine sauce ingredients

In a bowl whisk together 1/2 cup low-sodium soy sauce, 1/2 cup water, 1/4 cup brown sugar, 1 tablespoon hoisin sauce, 1 tablespoon rice vinegar, and 1/2 teaspoon sesame oil until the sugar is mostly dissolved.

Make slurry

In a small cup stir 1 teaspoon cornstarch with 1 tablespoon water to make a smooth slurry; set aside. (This will thicken the sauce toward the end.)

Cook aromatics

Wipe out the wok or use a clean large skillet. Heat 1 tablespoon neutral oil (and 1 teaspoon vegetable oil if using) over high heat until hot but not smoking. Add grated ginger and stir for 15–20 seconds, then add the minced garlic and red pepper flakes and stir 20–30 seconds until fragrant. Be careful not to burn the garlic.

Add sauce and reduce

Pour the prepared sauce into the pan with the aromatics and bring to a simmer over medium-high heat. Let it bubble gently for 2–3 minutes to meld flavors.

Thicken sauce

Stir the cornstarch slurry again and slowly whisk it into the simmering sauce. Cook for 30–60 seconds until the sauce thickens and turns glossy. If it becomes too thick, add up to 1–2 tablespoons water to reach a loose, clingy consistency.

Return beef to pan

Add the fried beef and most of the sliced scallions (reserve a few for garnish) to the sauce. Toss quickly to coat each piece thoroughly, cooking 1–2 minutes so the beef heats through and the coating becomes glossy.

Garnish and serve

Transfer the sauced beef to a serving platter or bowls over steamed rice or rice noodles. Sprinkle with toasted sesame seeds, remaining scallions, and optional fresh cilantro. Serve immediately.

Note on timing: Total active cook time is short; frying in batches and prepping sauce ahead will speed assembly. Adjust sugar or soy to taste for more sweetness or saltiness.