In a large skillet cook, ground beef and onion until meat is brown and onion is tender. Drain off fat. Stir in taco seasoning mix and water; cook and stir 10 minutes over medium heat. Stir in pinto beans, refried beans, undrained diced green chili peppers, cook 10 minutes. Set aside.
In a small bowl stir together sour cream, flour and garlic powder; set aside.
Place half of the tortillas in the bottom of a lightly greased 3-quart rectangular baking dish, cutting to fit and overlapping if necessary. Top with half of the meat mixture, half of the sour cream mixture, and half of the enchilada sauce. Repeat layers.
Bake, covered in a 350º oven for 35 to 40 minutes or until heated through.
Uncover and sprinkle with cheese.
Bake about 5 minutes more or until cheese is melted.