Preheat your oven to 350°F (175°C). Spray a 9x13-inch baking dish with non-stick cooking spray or lightly grease it with oil or butter.

In a medium-sized mixing bowl, combine the cooked chicken, 1 cup of shredded cheese, garlic powder, salt, and pepper. Stir until well mixed and set aside.

In a medium saucepan, melt the butter over medium heat. Once melted, whisk in the flour and stir continuously for about 1 minute to cook off the raw flour taste.

Slowly add the chicken broth while whisking to avoid lumps. Then add the sour cream, cream cheese (if using), and the entire can of diced green chiles. Whisk until smooth, and let the mixture simmer gently for about 5 minutes until it thickens slightly.

Stack and cut the tortillas in half or quarters to make layering easier.

Place a layer of tortilla halves at the bottom of the prepared dish, overlapping them slightly.

Spread one-third of the chicken mixture over the tortillas, then pour one-third of the sauce on top. Use a spoon to spread it out evenly.

Repeat the layering process two more times: tortillas, chicken, sauce. After the final layer, sprinkle the remaining 1 cup of cheese on top.

Bake uncovered for 30 minutes until the edges are bubbly and the top is lightly golden. For a crispier top, you can broil it on low for an additional 2-3 minutes—just keep an eye on it.

Let it sit for 5–10 minutes before slicing. Sprinkle with chopped parsley or cilantro if desired.