Beat egg into warm water and add to flour and salt to make a soft dough. Let stand for ten minutes, covered to keep from drying. Roll dough thin on a floured board. Cut into three-inch squares. Put a teaspoon of desired filling (listed below) in the center of the square and fold into a triangle, pressing the edges firmly together. Repeat with all squares.

Drop the pierogi into boiling salt water. Cook until the pierogi have all come to the top, (3 minutes). Drain in colander and rinse once in lukewarm water to prevent sticking.

Melt butter in frying pan and add pierogi. Toss in butter until brown and crisp.

Suggested fillings:
Sauerkraut, assorted meats, mashed potatoes, cottage cheese, mashed potatoes/cheese, prunes, mushrooms.