1️⃣ Marinate the Beef:

1. In a bowl, combine the sliced beef with soy sauce, oyster sauce, sugar, and cornstarch. Toss well and let it marinate for 15–20 minutes.

2️⃣ Sear the Beef:

1. Heat 2 tbsp of vegetable oil in a large skillet or wok over high heat. Add the beef in batches and sear for 1–2 minutes per side until browned. Remove from the skillet and set aside.

3️⃣ Sauté Garlic & Vegetables:

1. Add the remaining oil to the skillet. Toss in the whole garlic cloves and stir-fry for 1–2 minutes until golden and fragrant.
2. Add the sliced red and green bell peppers, and green chilies (if using), and stir-fry for 2–3 minutes until slightly tender but still crisp.

4️⃣ Make the Sauce:

1. In a small bowl, mix soy sauce, oyster sauce, hoisin sauce, beef broth, and black pepper. Pour the sauce into the skillet with the vegetables.
2. Add the cornstarch slurry and stir until the sauce thickens slightly.

5️⃣ Combine and Serve:

1. Return the seared beef to the skillet and toss everything together until coated in the sauce. Cook for an additional 1–2 minutes.