Mix chicken, 1 1/2 cup Mexican cheese, roasted peppers, chile peppers, and sour cream in a bowl until well combined.
Heat enchilada sauce in a 12-inch frying pan. Dip a tortilla in the sauce until well coated and slightly softened. Top with 1/2 cup chicken mixture.
Roll up tortilla and place seam side-down in the prepared baking dish. Repeat with remaining tortillas and chicken mixture. Top enchiladas with remaining sauce and sprinkle with remaining cheese. Spray a sheet of foil with cooking spray, and place it greased side down on the dish; seal to cover.
Refrigerate until ready to cook, up to 2 days.
When ready to bake, remove enchiladas from the refrigerator and let sit for 30 minutes. Keep foil cover on.
Preheat the oven to 350 degrees F (175 degrees C).
Bake in the preheated oven until bubbly, about 1 hour.