Steps
1. Marinate the beef strips in brewed coffee, soy sauce, brown sugar, and minced garlic for 15 minutes.
2. Heat olive oil in a pan over medium-high heat.
3. Add onions and bell peppers, stir-frying for 2-3 minutes until slightly tender.
4. Add the marinated beef strips, cooking until browned and cooked through, about 5-6 minutes.
5. Season with salt and pepper to taste.
6. Serve hot, optionally over cooked rice.