Remove the dough from the refrigerator and cut into 3 or 4 pieces. For those pieces you are not immediately working with, keep in the covered bowl.
using a rolling pin, roll out the dough until it fits a pasta maker.* Then roll to about 2 mm in thickness, about a 4 setting on my pasta maker.
Using a 3 inch cookie cutter, cut dough circles.
Add 2-3 tsp of filling, moisten the edges of the dough circle and fold over the dough to make a half moon shape.
Seal the edge well. Then using the tines of a fork make a decorative edge, which further seals the pierogi. Place the finished pierogi on a parchment covered cookie sheet.
Fill a large pot with water and add salt (it should taste like the sea in my opinion), and bring to a boil. You want a pot big enough to fit about 5-10 pierogi without crowding.
When the pierogi raise to the surface leave them for another 30 seconds then remove with a Spider Strainer and place them in a strainer.**
Using a large skillet add the butter and EVOO (in a 1:1 ratio) over medium low-high heat. When the oil begins to shimmer, add the pierogi and fry until just golden brown.
Add more butter/EVOO if necessary.
Remove the fried pierogi, place on paper towels, then serve. Sprinkle them with carmalized shallots (see recipe below) and sliced scallions. Also place a dollop of sour cream (or homemade yogurt) on top as well.