Mongolian Beef Recipe

Prep the beef

Trim any large pieces of fat from the flank steak. Freeze the steak for 20–30 minutes to firm, then slice very thinly against the grain into 1/8–1/4-inch pieces.

Place the sliced beef in a bowl. Add 1 tablespoon soy sauce, 1 tablespoon cornstarch, and 1/2 teaspoon baking soda (optional, for extra tenderness). Toss to coat, then let rest in the refrigerator for 15–20 minutes while you prepare the sauce and aromatics.

In a small bowl, whisk together 1/2 cup low-sodium soy sauce, 1/4 cup water, 1/4 cup packed brown sugar, 1 teaspoon rice vinegar, 1 teaspoon hoisin sauce, and 1/2 teaspoon sesame oil until the sugar dissolves. Taste and adjust: sauce should be boldly savory-sweet.

In a separate small cup, mix 1 teaspoon cornstarch with 1 tablespoon cold water to make a thin slurry. Set both bowl and slurry aside.

Mince 3 cloves garlic and 1 tablespoon fresh ginger. Slice 4 green onions into 1-inch pieces, separating whites from greens (reserve greens for garnish).

Heat a large skillet or wok over high heat until very hot. Add 1 tablespoon vegetable oil and swirl. Add half of the marinated beef in a single layer (do not overcrowd) and sear, stirring occasionally, until the edges brown and the beef is about 80% cooked, about 1–2 minutes. Remove to a plate. Repeat with the remaining 1 tablespoon oil and remaining beef. Keeping the beef seared in two batches prevents steaming and yields a better crust.

Wipe the pan lightly if there are burnt bits, then reduce heat to medium-high. Add the pan to the hot wok/skillet with any residual fond. Add the minced garlic and ginger and the white parts of the green onions; stir-fry 15–30 seconds until fragrant but not burned. If using, add 1/4 teaspoon dried red chili flakes now.

Pour the prepared sauce into the pan and bring to a simmer. Cook 1–2 minutes, stirring, to let flavors meld.

Give the cornstarch slurry a quick stir and pour into the simmering sauce, stirring constantly. The sauce will thicken quickly into a glossy coating—about 30–60 seconds.

Return the seared beef and any accumulated juices to the pan. Toss or stir continuously to coat the beef with the sauce and finish cooking, about 1 minute. Taste and adjust seasoning: add a teaspoon water if sauce too salty or a pinch more sugar if too tart.

Stir in the green onion greens and 1/2 teaspoon sesame oil, then remove from heat.

Spoon the Mongolian beef over steamed rice (about 1 cup rice per serving) or serve alongside fried rice. Garnish with toasted sesame seeds if desired and additional sliced green onions.