Preheat your oven to 400°F (200°C). This ensures that your casserole cooks evenly.
In a small bowl, mix together the chili powder, cayenne pepper, garlic powder, smoked paprika, onion powder, ground cumin, dried oregano, salt, and black pepper. This blend will provide a robust flavor to the dish.
In a 9x13 baking dish, combine the chopped onion, diced red bell pepper, uncooked brown rice, and the mixed seasoning. Stir well to ensure everything is evenly coated.
In a large bowl, whisk together the chicken broth, chopped green chilies, olive oil, and tomato paste until well combined.
Pour the broth mixture into the baking dish, stirring thoroughly to mix all ingredients together.
Add the corn, black beans, and cooked shredded chicken to the baking dish, mixing until everything is well incorporated.
Cover the baking dish with foil and bake for 65-70 minutes. This allows the rice to cook and absorb all the flavors.
Once done, remove the casserole from the oven, take off the foil, and sprinkle the shredded cheddar cheese on top.
Return the dish to the oven and bake for an additional 5-10 minutes until the cheese is melted and golden brown.
Let the casserole cool for 5-10 minutes before serving. Top with chopped cilantro, green onion, avocado, and salsa for added freshness and flavor.
Notes
For a vegetarian option, substitute the chicken with extra beans or tofu.