Sift flour and salt into a mixing bowl. Add egg; mix. Add water gradually until batter is stiff but smooth. Press dough flat on a plate or floured board. With a sharp knife, scrape small pieces of dough off and drop into boiling salted water. There should be only one layer at a time of spaetzle cooking. Boil gently for 5 to 8 minutes, or until done to your taste. Remove with perforated spoon and let drain. Serve as a side dish with meat. Serve right away or sauté the finished spaetzle in butter until golden and sprinkle with Parmesan cheese.