Prep all ingredients by dicing the onion and bell pepper, and mincing the garlic.
In a large skillet, heat olive oil over medium heat. Sauté onion and bell pepper for 5 minutes, then add garlic and cook for 1 minute.
Add ground beef to the skillet, cook until browned, and drain excess fat.
In a large bowl, combine beef mixture with black beans, corn, diced tomatoes, cooked rice, chili powder, cumin, salt, and pepper. Mix well.
Transfer mixture to a greased 9x13 inch baking dish and spread evenly. Top with shredded cheddar cheese.
Preheat oven to 350°F and bake for 25-30 minutes until cheese is melted and bubbly.
Let cool for 5 minutes before serving.