Mix the flour with the salt in a deep bowl. Add the egg, oil, and water to make a medium soft dough. Knead on a floured board until the dough is smooth. Caution: too much kneading will toughen the dough. Divide the dough into 2 parts. Cover and let stand for at least 10 minutes.
Combine the cottage cheese with the egg and season to taste with the salt.
Roll the dough quite thin on a floured board. Cut rounds with a large biscuit cutter, or as most old-world grandmothers did, with the open end of a drinking glass. Put the round in the palm of your hand. Place a spoonful of filling in it, fold over to form a half circle and press the edges together with the fingers. The edges should be free of filling. Be sure the edges are sealed well to prevent the filling from running out.
Place the pierogi on a floured board or tea towel and then cover with another tea towel to prevent them from drying out.
Once you have all the pierogies made, drop a few pierogies into a large quantity of rapidly boiling salted water. Do not attempt to cook too many at a time. Stir gently with a wooden spoon to separate them and to prevent them from sticking to the bottom of the pot. When they float remove them with a slotted spoon and place in a colander and drain thoroughly.
After all the pierogies are boiled and drained, pan fry in butter or bacon fat until golden brown. This dish can be served as a stand alone meal or paired up with kielbasa sausage.