Make A Mound Out Of The Flour, Then Make A Well In The Center. Place Egg Yolks And Eggs In The Center, Cutting In The Flour With A Knife And Adding Water And Salt. Knead Until Firm. Cut In Three Parts. Roll Dough Out Thinly, Then Cut Circles With A Cup. Place Small Amount Of Filling Off Center On Each Circle Of Dough. Fold Over And Seal By Moistening Edge With Water And Putting Pressure On Edges For A Firm Seal. Boil A Pot Of Water. Add Salt. Drop Pierogi Into Boiling Water. Cook Lightly For 5 Minutes Uskng A Low Flame. Remove Gently With Strainer Spoon And Brown In Butter In Frying Pan. Serve With Sour Cream.