2½ cups of flour (could be as much as 3 cups)
1 tsp salt
1 egg
2 tbs. sour cream (preferably regular)
1/2 cup lukewarm water

Mix all ingredients together, and knead just a bit. The dough should not be very smooth, and it should be quite sticky. Let stand covered with an inverted bowl for ~1/2 h before using. Take either all, or a portion of the dough, and roll it out until it is 1/16” thick. You will have to use plenty of flour to keep the dough from sticking to the rolling pin and rolling surface. You can also flip the dough several times as well. (Your work surface dictates how much you can roll out at one time.) The thickness is very important.

The Fillings

Although not necessary, it is a good idea to make the fillings the day before you make the pierogi and refrigerate it. This is a big cooking job. Breaking it into two days helps.

Sauerkraut (Kapusta) Filling

(makes 50-60 pierogi)

4 lbs sauerkraut
2 lb yellow onions
2 Tbs. sugar
salt

You can use canned sauerkraut. Drain and wash the sauerkraut to reduce the sharp acid flavor. You will have to wash and taste in stages to determine how sour you want it. Be careful not to overwash. You do want a bit of tartness. Finely chop the onions. Fry them in butter until they just become translucent, then add the sauerkraut and sugar. Either add more butter for frying, or add a combination of butter and olive oil. Fry to a golden brown color. Finally, add salt and pepper to taste. Plenty of pepper is needed to give the kraut a little zing.

Potato Filling

(makes 60-80 pierogi)

5 lbs of potatoes (red or Idaho are fine)
2 lbs of onions
salt
pepper