01 - Combine sliced beef, 2 tbsp soy sauce, 1 tbsp cornstarch, and sherry or rice wine in a medium bowl. Mix thoroughly and let marinate for 10 minutes.
02 - Whisk together soy sauce, oyster sauce, brown sugar, cornstarch, broth, sesame oil, and black pepper in a small bowl until smooth. Set aside.
03 - Bring a pot of water to boil. Blanch broccoli florets for 2 minutes, then drain and rinse under cold water to halt cooking process.
04 - Heat 1 tbsp vegetable oil in a large skillet or wok over high heat. Add beef and stir-fry for 2–3 minutes until browned. Transfer beef to a plate.
05 - Add remaining 1 tbsp oil to the pan. Sauté garlic and ginger for 30 seconds. Add blanched broccoli and stir-fry for 1–2 minutes.
06 - Return beef to the pan. Stir glaze mixture and pour over beef and broccoli. Cook, stirring constantly, until sauce thickens and coats everything evenly, about 2–3 minutes.
07 - Serve hot over steamed rice. Garnish with toasted sesame seeds and sliced scallions if desired.