Grandma's Barbeque Sandwiches a.k.a. Sloppy Joes

Grandma's Barbeque Sandwiches (a.k.a. The Best Sloppy Joe's)

1/2 cup celery, finely chopped
1 onion, finely chopped
2 lbs ground beef
1 small bottle of ketchup
1/4 cup brown sugar
1 Tbsp vinegar
1/4 tsp cinnamon
1/4 tsp allspice

Saute the celery and onions in a skillet with a little oil until they begin to soften. Add the ground beef and season with salt and pepper. Cook until the beef is no longer pink, being careful not to brown the celery and onions. Add the remaining ingredients (eyeball the amount of ketchup you need to make just enough sauce for the amount of beef in the pan) and simmer together for about 10 minutes or so. Serve on rolls.