Steps
1. In a bowl, mix brewed coffee, soy sauce, brown sugar, and minced garlic.
2. Marinate the sliced beef in the coffee mixture for 10 minutes.
3. Heat olive oil in a pan over medium-high heat.
4. Add the marinated beef and sear until browned, about 3-4 minutes.
5. Add bell pepper and onion slices, stir-fry for another 3 minutes until vegetables are tender-crisp.
6. Season with salt and pepper to taste.
7. Serve hot over cooked rice.