01 - Preheat oven to 375°F. Lightly grease a 9x13-inch casserole dish.
02 - In a large skillet over medium heat, sauté the diced onion, red bell pepper, and minced garlic for 3 to 4 minutes until softened and fragrant.
03 - Add the shredded chicken, drained black beans, cooked rice, chili powder, cumin, salt, and black pepper to the skillet. Stir thoroughly to combine and cook for 2 to 3 minutes until heated through.
04 - Spread a thin layer of salsa evenly across the bottom of the prepared casserole dish. Arrange 3 tortillas over the salsa, tearing as needed to fully cover the surface.
05 - Spoon half of the chicken and bean mixture over the tortillas. Drizzle with half of the enchilada sauce and half of the remaining salsa. Sprinkle 1 cup of shredded cheese evenly on top.
06 - Layer the remaining 3 tortillas over the cheese. Spread the rest of the chicken mixture on top, then drizzle with the remaining enchilada sauce and salsa. Top with the final cup of shredded cheese.
07 - Cover the dish tightly with aluminum foil and bake for 20 minutes.
08 - Remove the foil and continue baking for 10 more minutes until the cheese is bubbly and lightly golden on top.
09 - Remove from the oven and let the casserole rest for 5 minutes. Dollop with sour cream and sprinkle with fresh cilantro before serving.