thinly sliced celery
green pepper, chopped
Hamburger buns should be split and toasted.
Cook and stir the meat, onion and celery in a large skillet until the meat is brown.
Drain off the excess fat.
Stir in the cabbage, green pepper, ketchup, water, salt and mustard and heat to boiling, stirring occasionally.
Reduce the heat and cover.
Simmer until the vegetables are tender, about 25 minutes.
Spoon the mixture onto the bottom halves of the buns and top with the remaining halves.