Heat oven to 350°F. Spray 13x9-inch (3-quart) baking dish with cooking spray. In medium bowl, mix chicken, Monterey Jack cheese, roasted peppers, chiles and sour cream.
Spread about 2 teaspoons enchilada sauce on each tortilla. Top each with 1/2 cup chicken mixture. Roll up tortillas; arrange, seam side down, in baking dish. Top enchiladas with any remaining enchilada sauce. Sprinkle with Cheddar cheese. Spray sheet of foil with cooking spray; cover baking dish with foil, sprayed side down.
Bake 45 to 60 minutes or until hot. If desired, remove foil during last 5 minutes of baking time. If desired, serve with lettuce, tomato, avocado and additional sour cream.