Ruskie Pierogi (pierogi with Potatoes and Cheese)

Boil the cleaned, peeled baking potatoes in lightly salted water. Drain them, let them cool completely, then mash them using a fork. Finely dice the onion and saute it until golden. Crumble the cheese and combine it with the potatoes and onions. Season with salt and pepper. There should be small lumps of cheese and potatoes in the stuffing. Dump the flour onto a clean surface and make a small indentation in middle. Crack the egg into the indentation. Add the salt and a little bit of the lukewarm water. Knead until smooth, adding water and flour as necessary. This dough should be much like dough for pasta. Put a large, wide pot of salted water on the stove to boil. Divide the dough into parts. Keep what is not being used covered. Roll out the dough until it is thin. Using a glass or biscuit cutter, cut out circles. Place about half a tablespoon of filling on one side of each circle. Fold the dough over the filling (you get a half circle) and seal. Make sure none of the filling gets on the edge since that will make the thing come open when it boils. In tours, throw the pierogi into the boiling salt water, stir, and cover. When they float to the top, uncover the pot, lower the flame, and let them boil another two to three minutes. Remove them with a slotted spoon, and coat with a little clarified butter to keep them from sticking together. Serve topped with melted butter or rendered fat with bacon and with sour cream on the side. A few hints to ensure success: The dough should be fairly soft and rolled out quite thin. (I think around 2 mm). Guard against drying of the dough and the uncooked pierogi - keep them covered! The potatoes should be neither new nor wilted. The cheese should be neither too fatty, nor too sour. The Poles use something they call "twarog". This is essentially pressed curds. The closest thing I have seen in the States is "Farmer's Cheese", but well drained cottage cheese will work also. It is best to boil the potatoes the day before making the pierogi, so they have a chance to dry out a little. The cheese and potatoes should be smashed with a fork (pastry cutter works well too), not ground! The lumps will provide a more authentic taste. The onions should not be too brown, but only "golden". (I disagree with this totally. I prefer it when the onions are well browned. But I suppose that there is no strict rule here, as in most peasant food) The pierogi should be stuffed to the point that it seems that they won't close - they will. They should look plump and overstuffed. Make sure you close the dough pockets carefully to make sure they don't come open while cooking. After being removed from the water in which they are boiled, they should be coated in clarified butter, to prevent sticking. If you have any left over, they can be reboiled for a few minutes to warm them up, or as is traditional, fry them with a little bacon fat or butter until they brown a little.