Preheat your oven to 400 degrees.
In a large skillet, heat the avocado oil on medium heat. Once the pan is hot, sauté the chopped onion until it’s translucent.
1 1/2 tablespoons avocado oil, 1 large yellow onion
Add the garlic, spices, and salt to the skillet and stir until the onion is coated and the spices are fragrant (about 30 seconds).
3 garlic cloves, 1 tablespoon cumin, 1 tablespoon cayenne pepper, 1 tablespoon paprika, 3/4 teaspoon salt, 1/2 teaspoon pepper
Add the chicken and stir until it’s well coated with the onion and spice mixture.
6 chicken breasts
Stir in the tomato sauce and water, and let the chicken simmer uncovered in the sauce for 10 minutes. Remove the skillet from the heat.
2 15-ounce cans tomato sauce, 2/3 cup water
Using a slotted spoon or spatula, remove the chicken from the sauce and place in a large bowl with the refried beans and cilantro. Stir until the mixture is combined.
1 1/2 cups refried beans, 1/2 cup fresh cilantro
Pour 1 cup of the tomato sauce into the bottom of a 9″ x 13″ glass baking dish.
Place 2 tortillas in the pan (don't worry about them overlapping).
6 8-inch tortillas
Evenly spread 1/3 of the chicken mixture across the tortillas.
Pour 1/3 of the remaining tomato sauce over the chicken.
Sprinkle 2 cups of the shredded cheese over top.
6 cups shredded cheddar cheese
Repeat steps 8-11 two more times for a total of 3 enchilada casserole layers.
Place the enchilada casserole in the oven for 30 minutes or until it's hot and bubbling.
Let rest for about 15 minutes, and then serve.