In 12-inch skillet, heat oil over medium-high heat.
Add chicken, peppers and onion; cook about 4 minutes, stirring frequently, until chicken is no longer pink in center.
Remove from heat; drain.
Stir in chiles, 1 1/2 cups of the cheese and 1/4 cup of the enchilada sauce.
In bottom of ungreased 13x9-inch glass baking dish, evenly spread 1/2 cup of the enchilada sauce.
Spoon about 1/2 chicken mixture down center of each tortilla; roll up tortillas. Place each seam side down on enchilada sauce in baking dish, arranging in 2 rows.
Pour remaining enchilada sauce over enchiladas. Cover tightly with foil.
Bake 20 to 25 minutes or until hot and bubbly.
Sprinkle with remaining 1 1/2 cups cheese. Bake uncovered about 5 minutes longer or until cheese is melted.