Mongolian Beef Recipe

Slice beef

Trim any excess fat from the flank steak. Freeze the steak for 20–30 minutes until slightly firm (this makes slicing easier). Slice the steak thinly across the grain into 1/8–1/4-inch slices.

Marinate

Place the sliced beef in a bowl. Add 2 tablespoons soy sauce and 1/2 teaspoon baking soda; mix to coat evenly. Let rest 15 minutes at room temperature. The baking soda tenderizes the meat.

Coat with cornstarch

After marinating, drain any excess liquid. Add 1 cup cornstarch to the beef and toss until each slice is very lightly but evenly coated—shake off excess. This creates the characteristic glossy, slightly crisp exterior.

Heat 1/2 cup vegetable oil in a large heavy skillet or wok over medium-high heat until shimmering (about 350°F if using a thermometer). Working in batches so the pan isn’t crowded, add coated beef slices and cook 1–2 minutes per side until crisp and browned. Transfer fried beef to a paper towel–lined tray to drain. Keep oil hot between batches; reduce heat slightly if oil smokes excessively.

When all beef is fried, carefully discard oil from the pan leaving a thin film or wipe pan clean if you prefer less oil for the sauce step—reserve 1 tablespoon neutral oil for stir-frying the aromatics.

In a bowl or measuring cup combine 1/2 cup low-sodium soy sauce, 1/4 cup water, 1/2 cup packed brown sugar, 1 tablespoon hoisin sauce, 1 teaspoon rice vinegar, and 1/2 teaspoon sesame oil. Stir until sugar mostly dissolves.

In a separate small cup, dissolve 1 teaspoon cornstarch in 1 tablespoon cold water to make a slurry. Set aside.

Wipe the wok or skillet if you haven’t already and return to medium heat. Add 1 tablespoon neutral oil. When hot, add the finely minced ginger (1 tablespoon) and minced garlic (3 cloves). Sauté 20–30 seconds until fragrant but not browned.

Add the white parts of the sliced green onions and the optional 1/4 teaspoon red chili flakes; stir 15 seconds to soften the onions.

Pour the prepared sauce into the pan and bring to a simmer. Stir, then add the cornstarch slurry and continue to simmer 1–2 minutes until the sauce thickens to a glossy, clingy consistency. Taste and adjust: if too sweet, add a splash (1/2 tsp) of rice vinegar; if too salty, add a tablespoon of water and a touch more sugar if needed.

Return the fried beef and any accumulated juices to the pan. Toss quickly to coat each piece in the sauce and heat through 1–2 minutes. Add the green parts of the sliced scallions and 1/2 teaspoon toasted sesame oil; toss once more.

Transfer Mongolian beef to a serving platter, sprinkle with 1 teaspoon sesame seeds if using, and serve immediately over steamed white rice or alongside steamed greens.

Leftovers: store in an airtight container in the refrigerator up to 3 days. Reheat gently in a skillet over low heat to avoid overcooking the beef; add a splash of water if sauce has thickened too much.