Preheat your oven to 350°F (175°C) to ensure it is hot when you are ready to bake the casserole.
In a large skillet, heat the olive oil over medium heat. Once hot, add the diced bell pepper and sauté for about 5 minutes or until it softens and begins to become translucent.
Add the shredded cooked chicken, black beans, corn, diced tomatoes (with juice), ground cumin, paprika, and sprinkle in some salt and pepper. Stir to combine and cook for an additional 3-4 minutes until everything is heated through and well mixed.
In a large mixing bowl, combine the sautéed mixture with the cooked rice and half of the enchilada sauce. Mix well until all ingredients are evenly combined.
Grease a 9x13-inch baking dish with cooking spray or a little olive oil. Transfer the rice and chicken mixture into the dish, spreading it out evenly.
Pour the remaining enchilada sauce over the top of the casserole, ensuring even coverage.
Evenly sprinkle the shredded cheddar and Monterey Jack cheeses on top of the casserole for a cheesy finish.
Bake in the preheated oven for 25-30 minutes, or until the cheese is melted, bubbly, and lightly golden on top.
Carefully remove the casserole from the oven and allow it to cool for about 5 minutes before serving to help the flavors settle and prevent burns.
Garnish your casserole with fresh cilantro if desired, and serve with a dollop of sour cream on the side for added richness.
Notes
Garnish with fresh cilantro and serve with sour cream for added richness.