Melt 1/2 stick of butter in a pan with 1/2 teaspoon of salt. Add:

1 c. milk
1 beaten egg
2 1/2 c. flour until firm but sticky

Roll the dough thin, cut in 2 inch or 4 inch squares depending on how you like them. Place a small amount of filling a little to one side, fold over like a turnover, pinch the sides together into a triangle. Drop in boiling water until the Pierogi rises to the top. Serve with melted butter. I usually saute sliced onions in butter until done and drizzle over the Pierogi's for a special treat.

FILLING:

1 cooked potato
2 tbsp. potato water in which potato boiled
2 or more tbsp. of butter
1 c. Farmers cheese or Press cheese (sometimes I use cottage cheese, drain & if too moist, add bread crumbs to take up the moisture)
Salt & pepper to taste
2 or 3 tbsp. chopped onion if you desire

Combine.