Preheat the oven to 350°F and grease a 9x13-inch baking dish.

In a medium bowl, combine the shredded chicken, softened cream cheese, garlic powder, and half of the shredded cheese (about 1 cup). Mix until evenly coated.

Spoon equal portions of the chicken mixture down the center of each flour tortilla. Roll up and place seam-side down in the prepared baking dish. Pack them snugly but don’t overfill.

Melt the butter in a saucepan over medium heat. Whisk in the flour and the 1 tablespoon taco seasoning to form a roux; cook 30–60 seconds.

Gradually pour in the chicken broth while whisking until smooth. Heat the mixture until warm and slightly thickened.

Add 1/2 cup of the shredded cheese and whisk until incorporated.

Stir in the sour cream and the can of diced green chiles. Whisk just until the sour cream dissolves into the sauce; do not let it boil.

Pour the sauce evenly over the enchiladas. Sprinkle the remaining cheese on top.

Bake for 22–25 minutes until bubbling. Switch the oven to broil for 1–3 minutes to brown the cheese—watch closely to avoid burning.

Let rest for 5 minutes before serving.