Preheat the oven to 375°F (190°C).
In a large skillet, heat the olive oil over medium heat. Add the diced chicken and cook until fully cooked, about 5-7 minutes.
Add the sliced onion, bell pepper, and minced garlic to the skillet. Sauté for an additional 5-7 minutes until the vegetables are softened.
Stir in the chili powder, cumin, paprika, salt, and pepper. Cook for another minute to release the flavors.
In a large bowl, combine the cooked chicken and vegetable mixture with black beans, corn, salsa, and cooked rice. Mix well to combine all ingredients evenly.
Transfer the mixture into the prepared 9x13 inch casserole dish, spreading it out evenly.
Sprinkle the shredded cheese over the top.
Bake in the preheated oven for 20-25 minutes, or until the cheese is melted and bubbly.
Once done, remove the casserole from the oven and let it cool for a few minutes before serving.
Garnish with fresh cilantro if desired and serve hot.