My baba's pyrohy (perogies)

MMMMM----- Recipe via UNREGISTERED Meal-Master (tm) v8.02
 
       Title: My Baba's Pyrohy (Perogies)
  Categories: Side dish, Vegetables
       Yield: Lots (6 dozen or so)
 
   1 1/2 c Water
       3 tb Cooking oil
       1 ea  Egg
   4 1/2 c Flour
   1 1/2 ts Salt
      1/4 ts Pepper
       1 ea Medium onion, chopped
      1/4 c Butter
       3 c Potatoes, mashed
       1 c Cheddar Cheese (old), grated
       8 c Water, boiling
 
 Dough:
 
 Combine water, egg, oil and blend well.  Add flour and 1 tsp of the salt.
 Knead until smooth and soft (8 minutes approx).  Put dough into a 
 lightly oiled bowl, cover and rest for 20 minutes.
 
 Potato Filling:
 
 Combine (slightly cooled) mashed potatoes and grated cheddar in
 a bowl.  Saute onions in butter and add to mashed potatoes.  Add in
 the remaining salt (1/2 tsp) and pepper to taste.
 
 Take small pieces of the dough and roll it out until it is very thin 
 (1/8" or so).  Take a coffee mug (or round container of your choice)
 and cut our a circular shape.  
 
 Into the middle of the circle, drop 1/2 to 1 tsp of the potato mixture .  Fold
 the circle in half and seal edges by pinching them together.  This should
 leave you with a half moon shape.
 
 When you have completed sealing the pyrohy, it should be laid between
 two clean towels (this prevents it from drying out).  Once you have 
 made all of the pyrohy possible (when either your dough or potato runs out),
 set a pot of water to boil.
 
 In batches of 6-8 (depending upon how much your pot can hold), cook the
 pyrohy until they are floating.  Remove from water, place in a casserole dish
 and melt some butter or margerine on the batch of pyrohy to keep them 
 separated nicely.  Continue this until they are complete. 
 
 Now they're ready to eat.  Also at this time you can freeze them in batches 
 (I find that batches of a dozen work well).  I love pyrohy with sour cream,
 chives
 or fried onions and little pieces of bacon (shkvarky--optional).
 
 The next day, you may find that frying the pyrohy give you an even more 
 pleasant taste!
 
 MMMMM