Preheat your oven to 350°F (175°C).
In a large skillet, over medium heat, add the ground beef and diced onion. Cook until the beef is browned and the onion is translucent, about 5-7.
Add the minced garlic and cook for an additional 1.
In the skillet, stir in the black beans, corn, enchilada sauce, diced tomatoes, cooked rice, chili powder, cumin, salt, and black pepper. Mix well and let it simmer for about 5.
Transfer the mixture into a greased 9x13 inch baking dish. Spread it out evenly and sprinkle the shredded cheddar cheese over the top.
Bake for 25-30, or until the cheese is melted and bubbly. Let it cool for about 5 before serving.