This is the Ukrainian version of perogies. Some people use sauerkraut in place of potatoes. You can add meats or other fillings as well.
Clean, peal and cut potatoes. Put in large pan with water and cook until potatoes are soft enough to be mashed. Drain potatoes and put into large bowl. Mash using a potato masher, you want it to be chunky. Stir in cottage cheese and add salt and pepper to taste.
Beat eggs, mix in sour cream and add enough flour to make a dough. Roll out to about 1/4-1/2" thick. Cut dough into circles with the rim of a small plastic juice cup. Flatten circles slightly to make larger on a sheet of waxed paper, be careful not to make too thin or the filling will come out. Put a small ball of the filling in the middle of each circle fold remaining dough around and seal the edges. When the sheet of waxed paper is full, put them in the freezer.
When you are ready to cook them. Take the frozen pudaha out of the freezer and put in pan of boiling water, cook until they float.
Serve with melted butter and sour cream.