Step 1: Prepare and Marinate the Beef:Slice the beef thinly against the grain for tenderness.In a bowl, combine soy sauce, cornstarch, vinegar (or Shaoxing wine), sesame oil, and sugar.Add beef slices, mix well, and let marinate for 15–30 minutes at room temperature.
Step 2: Prepare the Sauce:In a small bowl, whisk together soy sauce, oyster sauce, hoisin sauce, brown sugar, and beef broth.Set aside the cornstarch slurry — you’ll add it later to thicken the glaze.
Step 3: Cook the Broccoli:Bring a pot of water to a boil and blanch broccoli for 1 minute (just until bright green).Drain and immediately plunge into cold water to stop cooking. Set aside.
Alternatively, you can stir-fry broccoli directly in the pan for a more roasted flavor.
Step 4: Stir-Fry the Beef:Heat 1 tbsp oil in a wok or large skillet over high heat.Add the marinated beef in a single layer. Sear undisturbed for 1 minute, then stir-fry until browned but not fully cooked.Remove beef from the pan and set aside.
Step 5: Build the Flavors:Add the remaining 1 tbsp oil to the pan.Sauté garlic, ginger, onion, and bell pepper (if using) for 30–45 seconds until fragrant.Add broccoli and stir well.
Step 6: Combine Everything:Return the beef to the pan.Pour in the prepared sauce and mix well.
Stir in the cornstarch slurry and cook for 2–3 minutes, stirring, until the sauce thickens and glazes the beef and broccoli.Taste and adjust seasoning (add soy sauce, sugar, or chili to your liking).
Step 7: Serve:Transfer to a serving platter, garnish with sesame seeds and green onions, and serve immediately.