Instructions

• Slice the 16 ounces flank steak very thinly against the grain. If needed, freeze the steak for about 10–15 minutes to firm it for easier slicing.
• In a small bowl, whisk together 6 tablespoons soy sauce, 4 teaspoons cornstarch, 2 tablespoons water, and 1 teaspoon granulated white sugar. Add the mixture to the sliced beef and stir to coat. Let the beef sit and marinate while you prepare the vegetables (about 10 minutes).
• Prepare the vegetables: thinly slice 1 medium onion, 2 medium bell peppers, 1 cup sliced mushrooms, 1 cup sliced zucchini, and 1 medium carrot thinly sliced. Grate 2 teaspoons fresh ginger.
• Heat a wok or large skillet over medium-high heat until hot. Add 1 tablespoon of the 3 tablespoons vegetable oil and swirl to coat the pan.
• Add the prepared onion, bell peppers, mushrooms, zucchini, and carrot to the pan. Stir-fry for 2 to 3 minutes until the vegetables are crisp-tender but not browned. Remove the vegetables from the pan and set them aside.
• Return the pan to high heat. Add the remaining 2 tablespoons vegetable oil and the 2 teaspoons grated fresh ginger, then immediately add the marinated beef in a single layer if possible. Stir-fry, breaking the beef apart as needed, until the pieces separate and just begin to change color (about 1–2 minutes).
• Add the cooked vegetables back into the pan and stir to combine. Stir-fry about 1 minute more, until the beef is cooked through and the sauce thickens slightly. Be careful not to overcook.
• Remove from heat and serve immediately, optionally over cooked rice.