01 - In a bowl, mix 1 tablespoon soy sauce, 1 tablespoon cornstarch, and 1/2 tablespoon grated ginger. Add the sliced beef, toss to coat, and marinate for 10 minutes.
02 - In a separate bowl, whisk together the remaining soy sauce, oyster sauce, rice vinegar, brown sugar, remaining ginger, water, and black pepper to make the stir fry sauce.
03 - Heat 1 tablespoon vegetable oil in a large wok or skillet over high heat. Add the marinated beef and stir fry for 2–3 minutes until browned but not overcooked. Remove beef and set aside.
04 - Add remaining oil to the pan. Stir fry broccoli, onion, carrot (if using), and garlic for 3–4 minutes until vegetables are just tender but still crisp.
05 - Return the beef to the pan. Pour in the stir fry sauce and stir to combine. Cook for another 2–3 minutes until the sauce thickens and everything is heated through.
06 - Drizzle with sesame oil, toss, and serve immediately over steamed rice or noodles if desired.