To Fry Perogies:
1 stick butter
1 C. chopped onions
Recipe
For filling: Combine mashed potatoes, grated cheese, melted butter and 4 eggs. Separate remaining egg and put yolk into the filling, the white into a small bowl and set aside.
For Dough: Combine ingredients for dough, adding a sprinkle of water if necessary. Roll out dough, press out circles. (A empty soup can can be used for circles or a glass but careful not to press to hard with glass so it doesn't break.) Brush egg white all around inner edge of circle. Put 1 TBSP of filling in center: top with another circle and press with fork to seal edges.
To Cook: Put water into deep pot and bring to boil. Drop into water a few at a time. They will sink to bottom and then float to surface, remove and drain.
In a heavy skillet melt butter and add onions. Put perogies in and heat, serve.
To freeze: Dust with flour, put on cookie sheet and freeze, store frozen perogies in ziploc bag.