01 - Combine sliced beef with soy sauce, Shaoxing wine, cornstarch, and black pepper in a bowl. Mix thoroughly to coat and marinate for 10-15 minutes.
02 - Whisk together soy sauce, oyster sauce, hoisin sauce, sugar, beef broth, and cornstarch in a small bowl until smooth. Set aside for later use.
03 - Heat 1 tablespoon vegetable oil in a large wok or skillet over high heat. Add marinated beef in a single layer and sear for 1-2 minutes until browned but not fully cooked through. Remove beef from wok and set aside.
04 - Add remaining oil to the wok. Toss in onions, bell peppers, garlic, and ginger. Stir-fry for 2-3 minutes until vegetables reach crisp-tender consistency.
05 - Return beef to the wok. Pour prepared sauce over the beef and vegetables. Toss everything together and stir-fry for 1-2 minutes until sauce thickens and beef is fully cooked. Season with additional black pepper to taste.
06 - Serve immediately while hot, accompanied by steamed rice.