3 tbsp. prepared mustard
1/2 lb. softened butter
3 tbsp. poppy seeds
1 chopped fine onion
Salt and pepper

Make an assembly line of the following: 16 slices ham 16 slices Swiss cheese 16 sq. pieces aluminum foil

Spread buns with butter mixture on one side. Top with slice of ham, then Swiss cheese. Wrap up whole thing in foil. Bake at 350 degrees for 20 minutes.