In a large saucepan or pot bring about 3 quarts lightly salted water to boiling.
Meanwhile, for spaetzle batter, in a medium mixing bowl stir together flour and salt. In a small mixing bowl stir together egg and milk. Stir egg mixture into dry mixture.
Hold a colander with large holes over the pan of boiling water; pour spaetzle batter into the colander and immediately press the batter through the holes with a wooden spoon. (Or, use a spaetzle maker following the manufacturer's directions.) Cook for 5 to 10 minutes or until spaetzle are tender but still firm, stirring occasionally. Drain well.
Melt margarine or butter; toss with bread crumbs. Sprinkle crumbs over hot spaetzle.