Preheat Oven:

Preheat your oven to 375°F (190°C).

Make the Filling:

In a large mixing bowl, combine the shredded chicken, 1 cup shredded cheese, sour cream, green enchilada sauce, garlic powder, cumin, salt, and pepper. Mix until well combined.

Prepare the Sauce:

In a medium saucepan, melt the butter over medium heat. Whisk in the flour and cook for 1–2 minutes, stirring constantly, until lightly golden. Gradually whisk in the chicken broth, ensuring there are no lumps. Cook for 3–4 minutes until the sauce thickens slightly. Stir in the sour cream and green enchilada sauce. Remove from heat and set aside.

Assemble the Enchiladas:

Spread a thin layer of the sauce on the bottom of a 9x13-inch baking dish. Spoon about 1/3 cup of the chicken filling into the center of each tortilla. Roll the tortillas tightly and place them seam-side down in the baking dish.

Add Sauce and Cheese:

Pour the remaining sauce evenly over the enchiladas, making sure they are fully coated. Sprinkle the remaining 1 cup of shredded cheese on top.

Bake:

Bake in the preheated oven for 20–25 minutes, or until the cheese is melted and bubbly.

Garnish and Serve:

Remove from the oven and let cool for 5 minutes. Garnish with chopped cilantro and sliced jalapeños if desired. Serve warm.