Healthy Sloppy Joes - cooking recipe

Ingredients

1 lb. ground sirloin
1 small onion
4 oz. no-fat sour cream
1 Tbsp. dry mustard
2 Tbsp. flour
6 Tbsp. catsup

Preparation

Brown sirloin with onion.
Add other ingredients.
Simmer 15 minutes or so.
Serve open-faced on bread of choice.