2. In small skillet, melt butter over a medium flame.
3. Saute the onion till soft and transparent.
4. Turn mixture into a bowl and cool slightly.
5. In the bowl combine add egg, mustard, caraway seed to the onion mixture.
6. Add rye bread cubes and toss till well mixed.
7. Shape into balls, using 1/2 cup mixture for each.
8. Arrange stuffing balls in roasting pan and bake for 20 minutes.