This recipe is from my mother's cousin, who ran a small polish restaurant in our area for over 40 years! Really makes a difference to have the right dough!
egg yolks, beaten
to 4 cups flour
SAUERKRAUT AND MUSHROOM FILLING
small onion, chopped, sauteed in 1 tbsp butter
mushrooms, chopped (a variety is recommended)
1Melt butter in warm milk. Add egg yolks. Pour flour and salt over warm milk and mix well. 'Cover and let dough rest for 10 minutes or more. Knead for 2 minutes. Let rest again. Roll out dough. Cut with a 4 inch circle. Put filling of your choice in center. Fold over and crimp to seal edges. Drop in a pot of boiling water until pierogi float to the top. Do not crowd pan to avoid sticking. Place pierogi on a cooling rack over a cookie sheet to cool. You can freeze them once cooled. Heat them in a pan of butter and sauteed onion or boil and cover with melted butter and onion.
2For filling--saute onions; add mushrooms and saute for a few minutes. Add sauerkraut and simmer for 3 to 4 minutes. Fill Pierogi