4 lb. lean roast beef
2 tbsp. vinegar
1 (32 oz.) bottle ketchup
4 c. chopped celery
3 onions, chopped
1 tbsp. salt (may be omitted)
2 tbsp. Worcestershire sauce
1 tsp. chili powder
2 c. water

Put all ingredients in a roaster. Cover and bake at 275-325 degrees for about 5 hours. As meat cooks, break it apart with a fork. Add extra water if it seems dry. Spoon on buns and serve. Fills 15-20 buns generously.