1. In a bowl, mix the beef with soy sauce, oyster sauce, cornstarch, and sugar. Let it marinate for at least 30 minutes.

2. Heat vegetable oil in a wok or large skillet over high heat.

3. Add the marinated beef and stir-fry for 2-3 minutes until it is browned. Remove the beef from the pan and set it aside.

4. In the same pan, sauté the onion, bell pepper, garlic, and ginger until fragrant.

5. Return the cooked beef to the pan and add beef broth and hoisin sauce. Stir well to combine.

6. Cook for another 2-3 minutes until the sauce has thickened.

7. Season with salt and pepper to taste.

8. Garnish with sliced green onions before serving.

Serve with rice or bread!