Preheat the oven to 375°F (190°C). Grease a 9x13-inch baking dish with cooking spray or olive oil.
In a large bowl, combine the cooked rice, chicken pieces, black beans, corn, diced tomatoes, olive oil, chili powder, cumin, garlic powder, onion powder, salt, and pepper. Mix well until all ingredients are evenly coated.
Pour the mixture into the prepared baking dish and spread it out evenly.
Cover the baking dish with aluminum foil and bake for 25 minutes.
Remove the foil, sprinkle the shredded cheddar cheese on top, and return to the oven. Bake uncovered for an additional 15 minutes, or until the chicken is cooked through and the cheese is melted and bubbly.
Remove from the oven and let it cool for a few minutes. Garnish with fresh cilantro before serving.