Beat egg slightly, add salt and enough flour to make a stiff dough. Roll out very thin and let remain on board one hour or until it is quite dry, but not brittle. Cut into 3 inch strips and place strips on top of one another. Then cut these into ½ inch strips, crosswise, cut again to form ½ inch squares. When dough is all cut into these little squares, toss them up lightly and spread to dry on the board. Drop them by handfuls into boiling soup, let boil 5 minutes before serving.