Preheat your oven to 350°F (175°C) so it’s hot and ready for your casserole.
In a large mixing bowl, combine the shredded cooked chicken, half of the enchilada sauce (about 7.5 ounces), taco seasoning, and chopped cilantro. Stir until everything is well mixed.
In your greased baking dish, spread a thin layer of the remaining enchilada sauce at the bottom. Take six flour tortillas and layer them over the sauce, covering the bottom completely.
Spoon half of the chicken mixture over the tortillas, spreading it out evenly. Sprinkle with 1 cup of shredded Mexican cheese blend.
Add another layer of tortillas, followed by the remaining chicken mixture, and top with another cup of shredded cheese. Finish with a final layer of tortillas.
Pour the remaining enchilada sauce over the top layer of tortillas and sprinkle with the last cup of shredded cheese.
Cover the baking dish with aluminum foil and bake in the preheated oven for 25 minutes. Then, remove the foil and bake for an additional 10-15 minutes, or until the cheese is bubbly and slightly golden.
Once out of the oven, let the casserole rest for about 10 minutes. This will make it easier to cut and serve.