Ma Foster's Sloppy Joes

Ingredients

1 pound beef
1 onion
1 cup ketchup
2 tablespoon vinegar
2 tablespoon sugar
2 tablespoon mustard
2 tablespoon worcestershire sauce
1 teaspoon celery seed

Instructions

In a frying pan, brown ground beef and onion. Add remaining ingredients and cook slowly for 15 minutes or more. Serve hot by scooping the mixture onto toasted buns.