Step 1: Preheat your oven to 350°F (175°C) to ensure even cooking.
Step 2: In a mixing bowl, combine the cooked shredded chicken, black beans, corn, diced bell peppers, salsa, cumin, garlic powder, onion powder, salt, and pepper. Mix until all ingredients are well incorporated.
Step 3: In a casserole dish, place a layer of 4 flour tortillas at the bottom, tearing them if needed.
Step 4: Spread half of the chicken and vegetable mixture over the tortillas, ensuring it covers them evenly.
Step 5: Sprinkle 1 cup of shredded cheddar cheese over the chicken mixture.
Step 6: Add another layer of tortillas, followed by the remaining chicken mixture and top with another cup of shredded cheese.
Step 7: Finish off with a final layer of tortillas and the remaining cheese on top.
Step 8: Cover the casserole with aluminum foil and bake for 25 minutes. Then remove the foil and bake for another 10-15 minutes, or until the cheese is bubbly and golden brown.
Step 9: Once baked, let the casserole sit for a few minutes before garnishing with fresh cilantro if desired. Serve warm and enjoy!