1/4 lb. soft butter
2 tbsp. horseradish
1 1/2 - 2 tsp. poppy seeds
2 tbsp. chopped onion
8-10 slices ham
8-10 slices Swiss cheese
8-10 hamburger buns

Mix first 4 ingredients together and spread on buns. Put 1 slice each of ham and cheese in bun. Wrap each sandwich in foil. Heat 20 minutes at 350 degrees. (Sandwiches may be made ahead and kept in refrigerator.)