Using a pasta machine, roll out the dough until it about 2mm in thickness. On my machine this is about a setting of 4.
Keeping the unused portions of the dough covered, use a 2.5 or 3 inch round cookie cutter and cut rounds of flour. Flous them to keep them from sticking together.
Take about 2 tsp of filling and place it a bit off center on the round.
Moisten one side on the round and fold over the filling making a half moon shape. Seal this well.
Set the pierogis on a parchment covered cookie.
Using a fork, indent the edge of each half moon for both a design and to firmly seal each packets.
In a pot of salted boiloing water, place in the pierogis. When they begin to float remove them and drain briefly.
In a fry pan place the butter and EVOO over medium high heat. When the butter and EVOO has melted and is shimmering, place the pierogis.
Fry the pierogis until jthey are ust beginning to brown.
Remove. These can be served hot, warmed or at room temperature.