Step 1: Marinate the Steak

1. In a bowl, mix soy sauce, cornstarch, sesame oil, and black pepper.
2. Add the sliced steak and coat evenly. Let it marinate for 15-30 minutes.

Step 2: Stir-Fry the Vegetables

1. Heat 1 tbsp oil in a wok or large skillet over medium-high heat.
2. Add onions and bell peppers, stir-frying for 2-3 minutes until slightly tender but still crisp. Remove and set aside.

Step 3: Cook the Steak

1. Add the remaining 1 tbsp oil to the pan.
2. Sear the marinated steak in batches for 1-2 minutes per side until browned.
3. Add garlic and ginger, stir-frying for 30 seconds until fragrant.

Step 4: Make the Sauce & Combine

1. In a bowl, whisk together soy sauce, oyster sauce, hoisin sauce, rice vinegar, brown sugar, and beef broth.
2. Pour the sauce into the pan and bring to a simmer.
3. Stir in the cornstarch slurry, cooking until the sauce thickens.
4. Return the peppers and onions to the pan, tossing everything together.

Step 5: Serve & Enjoy

• Serve hot over steamed rice or noodles.
• Garnish with sesame seeds or sliced green onions if desired.