Pennsylvania Dutch Mashed Potato Filling
["6 medium potatoes", "onion and celery (as desired)", "1/4 lb. butter", "1 egg", "1 c. milk", "salt and pepper to taste", "sage and poultry seasoning (if desired)", "parsley flakes (if desired)", "bread crumbs or toasted bread (to thicken)"]
["Cook potatoes, onion and celery in as little water as possible.", "Mash together potatoes, onion and celery with water they were cooked in.", "Add remaining ingredients.", "Add bread crumbs last, adding as much as necessary for desired thickness.", "Bake in a buttered casserole at 350\u00b0 for 45 minutes."]
["potatoes", "onion", "butter", "egg", "milk", "salt", "sage", "parsley", "bread crumbs"]