Barbecue Burgers

1/2 cup onion, chopped
2 tablespoons flour
1 tablespoon prepared mustard
1/4 teaspoon pepper
1 pound ground beef
6 tablespoons catsup
1/2 teaspoon salt
1 cup sour cream
8 hamburger buns

Brown onion and beef. Add flour, catsup, mustard, salt and pepper. Add sour cream.

Serve on lightly-toasted hamburger buns.