Thinly sliced beef gets a light coating and a quick sear, then finishes in a sauce built from soy, ginger, garlic, and brown sugar — the combination that defines this Chinese-American restaurant staple. The whole dish moves fast and pairs well with steamed rice or noodles. Dinner is ready in about 30 minutes.
Prepare the Beef: Thinly slice the flank steak against the grain into bite-sized strips.
Coat and Sear the Beef: Toss the beef strips with cornstarch until evenly coated. Heat 2 tablespoons of vegetable oil in a large skillet or wok over medium-high heat (190°C/375°F) until shimmering. Sear the beef in batches to avoid overcrowding, cooking each side for about 1-2 minutes until browned. Remove and set aside.
Make the Sauce: In the same skillet, add the remaining tablespoon of oil. Sauté the garlic and ginger until fragrant, about 30 seconds. Add soy sauce, water, and brown sugar, stirring until the sugar dissolves and the sauce slightly thickens, about 2-3 minutes.
Combine Beef and Sauce: Return the beef to the skillet, stirring to coat all pieces evenly with the sauce. Cook for an additional 1-2 minutes, allowing flavors to meld. Adjust seasoning with salt and pepper as desired.
Garnish and Serve: Transfer the Mongolian Beef to a serving dish, garnishing with sliced green onions. Serve hot over a bed of steamed rice.
Notes
For a deeper flavor, marinate the beef briefly in the soy sauce mixture before cooking.
Substitute tamari for soy sauce for a gluten-free version.
The dish pairs well with a light, floral white wine or jasmine tea.