Mongolian Beef Recipe

Slice and marinate

Trim excess fat from the flank steak and freeze 20–30 minutes until slightly firm (this makes slicing easier). Using a sharp knife, slice against the grain into 1/8–1/4 inch (3–6 mm) thin strips. Place the strips in a bowl.

Add 1 tablespoon soy sauce, 1 tablespoon Shaoxing wine, egg white, 3 tablespoons cornstarch, 1/4 teaspoon salt, and 1/8 teaspoon black pepper to the beef. Mix thoroughly so each strip is lightly coated. Let marinate 15–20 minutes at room temperature (or up to 1 hour refrigerated).

When ready to cook, heat 2 tablespoons vegetable oil in a large nonstick skillet or wok over medium-high heat until shimmering.

Working in a single layer and in batches to avoid steaming, add marinated beef strips to the hot pan in an even layer. Sear without moving for 30–45 seconds, then stir-fry 1–2 minutes until just browned but not fully cooked through. Remove browned beef to a plate and reserve. Repeat with remaining beef, adding more oil if needed.

Prepare sauce

While the beef rests, whisk together 1/2 cup low-sodium soy sauce, 1/4 cup dark brown sugar, 1/2 cup water, 1 teaspoon hoisin sauce, 1 teaspoon grated ginger, and 2 minced garlic cloves in a bowl until sugar mostly dissolves. If you want heat, stir in chili paste to taste—start with 1/2 teaspoon for mild, 1 teaspoon for medium, 1.5–2 teaspoons for hot.

Optional step to thicken: mix 1 teaspoon cornstarch with 1 tablespoon water to make a slurry and set aside (use later if you prefer a thicker glaze).

Pour the prepared sauce into the hot empty pan (use medium heat). Bring to a simmer and cook 1–2 minutes to meld flavors. If you prefer a thicker sauce, stir in the cornstarch slurry and simmer 30–60 seconds until sauce thickens and becomes glossy.

Add 1 tablespoon vegetable oil to the pan if sauce has reduced too much. Add sliced yellow onion (cut into 1/4-inch slices) and cook 2–3 minutes over medium-high heat until slightly softened but still with some bite.

Return the reserved beef and any accumulated juices to the pan with the onions and toss to coat in the sauce. Stir-fry together 1–2 minutes until beef is heated through and sauce clings to the meat. Do not overcook; the beef should remain tender.

Slice scallions into 1-inch pieces and add most of them to the pan in the last 30 seconds to wilt slightly while retaining color. Drizzle 1 teaspoon sesame oil over the finished dish and toss once.

Taste and adjust seasoning: add a pinch of salt or a splash of soy if needed, or more chili paste for heat.

Serve the Mongolian beef immediately over steamed white or brown rice (about 1 cup cooked rice per serving). Garnish with remaining scallion pieces and a sprinkle of toasted sesame seeds if using.

Recommended doneness: serve hot with extra sauce on the side. Leftovers keep in the refrigerator 2–3 days; reheat gently to avoid overcooking the beef.