cuban bread rolls

- 4 Cuban bread rolls (or substitute with a baguette or hoagie rolls) - 1/4 cup yellow mustard - 8 slices Swiss cheese - 8 slices cooked ham - 1 lb roast pork, thinly sliced (leftover roast pork works well) - 8 slices dill pickles - 2 tablespoons butter, softened