Kartoffelsuppe (Potato Soup)

Beef soup bone;
3 quarts water;
salt and pepper to taste;
2 medium onions, chopped;
1/2 cup chopped celery;
6 to 8 potatoes peeled/boiled

Bring soup bone to boil in water. Add rest of ingredients except
potatoes and simmer for 2 hours. Remove bone.
Mash potatoes thoroughly, add to broth and reheat.
Add parsley

Serves 6 to 8