Marinate the beef: In a bowl, mix sliced beef with soy sauce, cornstarch, vinegar, and 1 tbsp oil. Let sit for 15–20 minutes while prepping other ingredients.
Make the sauce: In a small bowl, whisk together soy sauce, oyster sauce, hoisin sauce, cornstarch, broth, brown sugar, and black pepper. Set aside.
Sear the beef: Heat 1 tbsp oil in a large wok or skillet over high heat. Add beef in a single layer, cook for 1–2 minutes per side until browned (don’t overcrowd). Remove and set aside.
Stir-fry the vegetables: Add remaining oil to the pan. Toss in garlic, onion, and bell peppers. Stir-fry for 2–3 minutes until slightly tender but still crisp.
Combine: Return the beef to the pan. Pour the sauce over everything and stir until the sauce thickens and coats the beef and vegetables (about 2 minutes).
Serve: Garnish with green onions if desired. Serve hot over steamed rice or noodles.
🍚 Tips & Variations
For heat 🌶️: Add sliced chili peppers or 1 tsp chili garlic sauce.
For extra tenderness: Add 1/4 tsp baking soda to the beef marinade.
For richer flavor: Finish with a drizzle of sesame oil at the end.
Would you like me to give you a slow cooker version or the 15-minute quick stovetop version next?
