Dough   
 
1 egg                   2 tbsp sour cream
1 c. milk               1 c water
Mix together
 Add at least 4 1/2 cups of flour.  Them keep adding more as needed to make a nice dough.
I knead it for at least 5 minutes.
 
Potato filling
While potatoes are cooking chop at least 1 onion  & sauté with about 2-3 sticks butter.
About 5 lbs. cooked potatoes
 When done add about 6-8 slices yellow cheese depending on your taste.
Add some of the butter & onion mixture to potatoes.
Roll dough & I use a round cutter or use a jar to make your perogi.
Put in boiling water & cook at least 5 minutes.  Do not let it BOIL very hard as it will break them.
Drain & pour over  the rest of the melted butter & onions.