Steps
1. Preheat the oven to 375°F (190°C).
2. In a large mixing bowl, combine the cooked rice, beans, shredded cheese, onions, bell peppers, minced garlic, cumin, chili powder, salt, and pepper. Mix well.
3. Transfer the mixture to a greased casserole dish and spread it out evenly.
4. Bake in the preheated oven for 20-25 minutes, or until the cheese is melted and bubbly.
5. Remove from the oven and let it cool for a few minutes before serving.
6. Serve the cheesy bean and rice casserole with your choice of optional toppings, such as sour cream and chopped cilantro.