Ma Foster's Sloppy Joes

Ingredients

450 gr beef
1 onion
240 ml ketchup
30 ml vinegar
26 gr sugar
30 ml mustard
30 ml worcestershire sauce
2 gr 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.