Grandma E'S Famous Sloppy Joes
["1 Tbsp. butter", "1/2 c. ketchup", "2 Tbsp. vinegar", "2 Tbsp. brown sugar", "2 tsp. mustard", "1 c. water", "4 tsp. flour", "1 1/2 to 2 lb. cooked hamburger"]
["Mix water with flour. Add sauce and cook until thick (boil about 2 minutes). Add to cooked hamburger."]
["butter", "ketchup", "vinegar", "brown sugar", "mustard", "water", "flour", "hamburger"]