Steps
1. In a bowl, marinate the beef slices with soy sauce, oyster sauce, and cornstarch. Let it sit for 10 minutes.
2. Heat vegetable oil in a pan over medium-high heat.
3. Add minced garlic and sauté until fragrant, about 30 seconds.
4. Add the marinated beef to the pan and stir-fry for 3-4 minutes until browned.
5. Toss in the bell pepper and carrot, cooking for another 2-3 minutes until vegetables are tender-crisp.
6. Season with salt and pepper to taste, and sprinkle with chopped green onion before serving.