1 stick butter
2 tbsp. prepared mustard
1 tbsp. Worcestershire sauce
2 tbsp. poppy seeds
1 sm. onion, chopped
1 1/2 lbs. sliced or chipped ham
1 doz. poppy seed rolls (lg.)
1 1/2 lbs. sliced Swiss cheese

Mix the first 5 ingredients and cook for 5 minutes over medium high heat. Cut rolls; put ham, cheese, and approximately 1 tablespoon topping on each sandwich. Wrap individually in foil. Bake 20 minutes at 350 degrees.