Start by placing the boneless skinless chicken breasts into your crockpot alongside the red enchilada sauce, fire-roasted tomatoes, green chiles, and taco seasoning packet. Mix everything gently to ensure that the chicken is well-coated in the flavorful sauce mixture. Set your crockpot on low for 4-6 hours or on high for 3-4 hours, allowing the chicken to cook slowly until tender.
Once your cooking time is complete, take two forks and shred the cooked chicken directly in the crockpot for easy mixing. After shredding, add half of your shredded cheese along with black beans, frozen corn, and tortilla wedges into the pot. Gently stir everything together so that all ingredients are evenly distributed before topping with the remaining cheese.
Cover the crockpot again after adding all ingredients and set it to cook for an additional 20-30 minutes on high or until the cheese has melted beautifully over the top of your casserole.
Once everything is cooked through, serve hot straight from the crockpot! Pair this hearty casserole with fresh toppings such as chopped cilantro, diced avocados, or sour cream.