01 - Preheat oven to 375°F. Grease a 9x13-inch baking dish with oil or cooking spray.
02 - In a large skillet over medium heat, sauté diced onion and bell pepper in a splash of oil for 4 to 5 minutes until softened. Add minced garlic and cook for 1 minute until fragrant.
03 - Stir in corn, black beans, shredded chicken, ground cumin, chili powder, smoked paprika, salt, and black pepper. Cook for 2 to 3 minutes until heated through. Remove from heat.
04 - Spread 1/2 cup enchilada sauce evenly on the bottom of the prepared baking dish.
05 - Layer 1/3 of the tortillas over the sauce, overlapping slightly to cover the base.
06 - Top tortillas with half the chicken-bean mixture, 1/2 cup enchilada sauce, and 2/3 cup shredded cheese.
07 - Layer remaining 1/3 tortillas over cheese, then top with remaining chicken-bean mixture, 1/2 cup enchilada sauce, and 2/3 cup cheese.
08 - Top with final layer of remaining tortillas, pour remaining enchilada sauce over top, and sprinkle with remaining cheese.
09 - Cover baking dish tightly with aluminum foil and bake for 25 minutes.
10 - Remove foil and bake for 10 to 15 minutes until sauce is bubbly and cheese is golden brown.
11 - Allow casserole to rest for 10 minutes. Top with sour cream and desired garnishes before serving.