Sliced ham
Swiss cheese slices
Pan rolls

Filling:

1/2 c. (1 stick) butter
3 tbsp. mustard
3 tbsp. Poppy seed
1 small onion chopped finely
2 tbsp. Worcestershire Sauce

Soften butter, add rest of filling ingredients. Spread mixture on both sides of sliced rolls. Put ham and cheese slices on rolls. Warm 10 minutes in 350°F oven or until cheese melts.