Sour Cream-Chili Bake

1 pound ground beef

1/4 cup chopped onion

1 10-ounce can hot enchilada sauce

1 8-ounce can tomato sauce

1 15-ounce can pinto beans

2 1/3 cups crushed corn chips

1 cup shredded sharp American cheese (4 ounces)

1 cup dairy sour cream

In 2-quart microwave safe casserole dish, crumble ground beef. Add onion; cover and microwave on high until meat is brown (about 5 minutes, depending the wattage of your microwave). Stir several times to break up meat. Drain off excess fat. Stir in enchilada sauce and tomato sauce. Microwave, covered for 5 more minutes, stirring once. Drain beans; stir beans, 1 cup of the corn chips, and 3/4 cup of the cheese into meat. Microwave, covered, 6 minutes, stirring once. Stir, then spread sour cream over top; sprinke remaining chips and cheese over top. cook just until sour cream is hot, 30 to 45 seconds. Serves 6 to 8.