In small skillet heat margarine until bubbly and hot; add bread and sauté, stirring constantly, until bread has absorbed the margarine and is browned. Set aside.  Measure out and reserve 2 tablespoons flour. in mixing bowl combine remaining flour with potatoes, egg, and seasonings, mixing well; portion dough into 24 equal mounds.  Flour hands with reserved flour and shape mounds into balls; press 3 bread cubes into each ball and seal closed, forming dumplings.
  In 5 quart saucepan or Dutch oven bring water to a boil; use slotted spoon to gently lower several dumplings into water (they will sink to the bottom); when dumplings rise to surface, cook for 3 to 5 minutes longer. With slotted spoon, remove dumplings to warmed serving platter.  Repeat procedure with remaining dumplings.  These dumplings are good as an accompaniment to Sauerbraten.
Makes 12 servings of 2 dumplings each.