Preheat Oven: Preheat oven to 350°F (175°C). Grease a 9×13 inch baking dish.
Mix Sauce: In a medium bowl, combine sour cream, green enchilada sauce, diced green chiles, garlic powder, onion powder, salt, and pepper.
Add Chicken: Stir in cooked chicken and 1 cup of shredded cheese until well combined.
Assemble: Spread a thin layer of mixture in the baking dish. Fill each tortilla with about 1/3 cup of chicken mixture, roll up, and place seam-side down in the dish.
Top with Cheese: Sprinkle remaining 1 cup cheese over the top. Cover with foil.
Bake: Bake covered for 25 minutes. Remove foil and bake 5 more minutes until cheese is melted and bubbly.
Rest and Serve: Let stand 5 minutes. Garnish with fresh cilantro if desired.