Steps
1. In a bowl, marinate the sliced beef with soy sauce and sesame oil for 15 minutes.
2. Heat vegetable oil in a pan over medium-high heat.
3. Add garlic and ginger, sauté for 30 seconds until fragrant.
4. Add the marinated beef to the pan, cooking for about 3-4 minutes until browned.
5. Toss in the bell peppers and broccoli, stir-frying for an additional 3-5 minutes until the vegetables are tender-crisp.
6. Season with salt and pepper to taste.
7. Serve hot over cooked rice if desired.