2 cups unbleached all-purpose flour
1/2 teaspoon salt
1 large egg
1/2 cup sour cream
1/4 cup butter, room temperature
1 cup warm mashed potato
1 cup sharp cheddar cheese, shredded
1/4 cup butter
2 large shallots, diced; OR one medium onion, thinly sliced
Sauté the shallots in the butter until they begin to brown.
To make the dough: Mix together the flour and salt.
Add the egg to the flour and combine. The dough will be quite clumpy at this stage.
Work in the sour cream and soft butter until the dough comes together in a slightly rough, slightly sticky ball.
Using just your fingertips, knead and fold the dough without adding additional flour until the dough becomes less sticky but still quite moist.
Wrap the dough well in plastic wrap and refrigerate for 30 to 60 minutes(up to 48 hours).
To make the filling: Combine the warm mashed potato and cheese. Stir and mash until the cheese is melted and the filling is cool to the touch.
To fill the pierogi: Separate half the dough and roll it out until it is 1/8″ thick. Use a 2″ round cutter to cut circles of dough. Repeat with the other half of the dough. Save the scraps; these can be snipped into small pieces and added to simmering soups.
Place 2 teaspoons of filling on each round of dough. Gently fold the dough over, forming a pocket around the filling. Pinch the edges of the pierogi to seal, then seal again with the tines of a fork. At this point the pierogi can be frozen for up to 4 weeks, or refrigerated overnight, or cooked in a large stockpot of boiling salted water
To finish the pierogi: Fill a large pot with water and set to boil.
Once water is boiling, add in 10 pierogi at a time. Boil until the pierogi float to the surface (about 8 minutes).
After all of your pierogi are boiled, drain the water and set pierogi aside.
Peel and dice your remaining shallots.
Melt your butter in a large skillet on medium heat.
Add the drained pierogi and cook for about 7 minutes on each side until their outsides are golden and crisp.
Serve hot and top with sour cream, applesauce, chopped chives, or other condiments.