Preheat oven to 375

Slice rolls in half and add to baking pan

Add butter, seeds, mustard, onion and Worcestershire sauce to small pan. Heat on low until all ingredients are mixed and butter is melted

Spread on small amount of sauce to bottom and top half of of buns

Build sandwich .. ham and swiss

Replace roll tops and drizzled the remaining sauce over the sandwiches

Bake for 15 min, or until cheese is melted