1/2 c. butter, softened
1/4 c. chopped onion, fine
1/4 c. mustard
1 tbsp. poppy seed
Ham slice/Swiss cheese slice

Mix all above ingredients. Spread mixture on both side of buns. Place one slice ham/cheese on each bun. Bake 15 minutes at 350 degrees.

Can be frozen. If frozen, you must bake longer.