Ingredients

1/2 Cup softened butter
1/4 Cup finely grated onion
1/4 Cup prepared mustard
1 Tablespoon poppy seeds
6 hamburger buns
6 Slice ham
6 Slice Swiss cheese

Instructions

Blend butter, onion, mustard and poppy seeds. Spread insides of buns with butter mixture, saving some for the outside tops. Place a slice of ham and a slice of cheese on each bun and close buns. Spread reserved butter mixture on top of the buns. Arrange on cookie sheet and bake at 350 degrees for 15 minutes. Serve at once.