1 stick butter
1 tsp. minced onion flakes
1 1/2 tbsp. mustard
1 tbsp. poppy seeds
1 tsp. Worcestershire sauce
2 pkg. Party Rolls
8 oz. boiled ham
6 oz. Swiss cheese

Prepare sauce with the first 5 ingredients. Slice open each package of rolls all at once. Spread sauce over rolls. Place a slice of ham and a slice of Swiss cheese on each. Close. Wrap tightly with foil and refrigerate overnight. Preheat oven to 325 degrees and bake 15-20 minutes or until cheese has melted.