Creating your Mexican Chicken Casserole is easier than you might think. Just follow these steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C).
2. Cook Chicken: If you haven’t pre-cooked the chicken, boil or sauté it until fully cooked. Shred and set aside.
3. Sauté Vegetables: In a skillet, heat olive oil over medium heat. Add diced onion and cook until translucent, about 4-5 minutes.
4. Mix Ingredients: In a large bowl, combine shredded chicken, black beans, corn, diced tomatoes, salsa, cooked rice, cumin, chili powder, garlic powder, and half of the shredded cheese. Mix until well combined.
5. Season: Add salt and pepper to taste, mixing thoroughly.
6. Assemble Casserole: Spread the mixture evenly into a greased 9×13 inch baking dish. Top with the remaining shredded cheese.
7. Bake: Cover the dish with aluminum foil and bake for 25 minutes. Then, remove the foil and bake for an additional 10-15 minutes or until the cheese is bubbly and slightly golden.
8. Garnish: Once baked, allow it to cool slightly. Garnish with fresh cilantro before serving.
9. Serve and Enjoy: Slice into portions and serve hot.

These steps will guide you in creating a flavorful and hearty Mexican Chicken Casserole that everyone will love.