Wash potatoes and pierce with a fork, then boil half an hour with skins on until fork tender.
Peel and mash the potatoes.
In a sauce pan mix together butter, beaten egg yolks, milk, onion and salt and pepper. Cook until well blended and then mix into the mashed potatoes and mash together well.
We hands and form into balls with a cheese cube in the center. Pack potatoes around the cheese.
Dip the balls into beaten egg whites and then roll into the saltine cracker crumbs.
Drop into the hot vegetable oil and cook until golden brown.
Refrigerate for 12 to 24 hours and then bake in a 200 degree oven for 1 hours
Notes
This recipe can easily be doubled to feed a crowd.