To prepare dough: Mix eggs, sour cream, salt and butter.
Blend in flour; Knead dough very well until easy to handle
To prepare filling: Mix cottage cheese, Farmer's cheese, onion, butter, potatos, eggs, salt and pepper, and fried half of the pork together, blending well
To make pierogi: Roll out dough thin and cut out 1½-inch (1½-inch) diameter circles
Place 1 tablespoon filling into center of each and seal together
Cook 6 at a time in boiling salted water for about 5 minutes until they float to top
Remove with slotted spoon and drain
Sauté with margarine on both sides to marinate slightly before serving plate
Spoon remaining fried pork bits over top
