Start by gathering all your ingredients. Chop the onion, avocado, and tomato as needed. Cut the whole-wheat tortillas into small pieces, which will act as the base of your casserole.
In a large skillet over medium heat, add the lean ground turkey and chopped onion. Cook until the turkey is browned and the onions are translucent, about 5-7 minutes. Make sure to break the turkey into small pieces as it cooks.
Once the turkey is cooked through, stir in the cumin, cayenne pepper, black pepper, sea salt, and salsa. Mix well and let the mixture simmer for about 5 minutes to allow the flavors to meld.
Preheat your oven to 350°F (175°C). In your baking dish, layer half of the tortilla pieces on the bottom. Pour half of the turkey and salsa mixture over the tortillas. Sprinkle half of the reduced-fat cheddar cheese on top. Repeat these layers with the remaining tortillas, turkey mixture, and cheese.
Cover the baking dish with aluminum foil and bake in the preheated oven for 20 minutes. Remove the foil and bake for an additional 10 minutes, or until the cheese is melted and bubbly.
Once baked, remove the casserole from the oven and let it cool for a few minutes. Top with diced avocado and tomato, if desired. Serve warm and enjoy your delicious Skinny Taco Casserole!
