Classic Mongolian Beef Stir-Fry

1.Pat the flank steak slices dry with paper towels. In a medium bowl, toss the beef with cornstarch until evenly coated; set aside.

2.In a small bowl, whisk together soy sauce, water, brown sugar, and crushed red pepper flakes (if using) until the sugar dissolves; set the sauce mixture aside.

3.Heat 1 tablespoon of vegetable oil in a large skillet or wok over medium-high heat until shimmering. Add the beef in a single layer (work in batches if necessary) and sear without stirring for about 1 minute to develop a crust. Stir-fry the beef for another 1-2 minutes until browned but not fully cooked through. Remove beef from the skillet and set aside.

4.Add the remaining 1 tablespoon of vegetable oil to the skillet. Add minced garlic and grated ginger; stir-fry for about 30 seconds until fragrant, taking care not to burn.

5.Return the beef to the skillet along with the scallion pieces. Pour the prepared soy-ginger sauce over the beef and scallions. Stir well to combine and cook for 2-3 minutes, allowing the sauce to thicken and coat the beef evenly.

6.Taste and season with salt and freshly ground black pepper as needed. Remove from heat.

7.Serve the Mongolian beef stir-fry immediately over steamed white rice.