Steps
1. In a bowl, mix the beef with soy sauce, oyster sauce, cornstarch, and a pinch of salt and pepper. Let it marinate for 15 minutes.
2. Heat the vegetable oil in a pan over medium-high heat. Add minced garlic and stir-fry for 30 seconds.
3. Add the marinated beef to the pan and stir-fry until browned, about 2-3 minutes.
4. Add the sliced green bell pepper and continue to stir-fry for another 2-3 minutes until the peppers are tender-crisp.
5. Serve hot over cooked rice.