Mix flank steak slices with 1 tablespoon cornstarch, 1 tablespoon water, and 1 tablespoon soy sauce in a bowl. Let marinate for 15 minutes while prepping vegetables and sauce.
1 lb flank steak, 2 tbsp soy sauce, 2 tbsp cornstarch, 1 tbsp water
Boil broccoli florets in salted water for exactly 1 minute, then drain and plunge into ice water to stop cooking. They should remain bright green and crisp-tender.
3 cups broccoli florets
Heat 2 tablespoon vegetable oil in wok over medium-high heat until shimmering. Add half the marinated beef in a single layer and cook 1-2 minutes per side until browned. Remove to plate and repeat with remaining beef.
3 tbsp vegetable oil, 1 lb flank steak
Add 1 tablespoon vegetable oil to same wok. Cook minced garlic and ginger for 30 seconds until fragrant. Stir in oyster sauce, soy sauce, brown sugar, and blanched broccoli.
3 tbsp vegetable oil, 3 cloves garlic, 1 tbsp fresh ginger, 3 tbsp oyster sauce, 2 tbsp soy sauce, 1 tbsp brown sugar, 3 cups broccoli florets
Return beef to wok and toss everything for 1 minute until sauce coats evenly. Remove from heat, drizzle sesame oil over top, and serve immediately over steamed rice.
1 lb flank steak, 1 tsp sesame oil
