1. Preheat your oven to 325 degrees.
2. Grab a package of Sweet Hawaiian Rolls (12 rolls per package).
3. Carefully remove the rolls from the package and slice them in half (trying your best to keep them connected).
Separate the top half from the bottom half.
4. In a glass measuring cup melt 4 Tb butter. Add 1/4 C minced yellow onion, 3/4 Tb stone ground mustard (or honey mustard), 3/4 Tb poppy seeds and 1/2 tsp Worcestershire sauce. Stir well to combine.
5. Spread the mixture over the inside of both the bottom and top layer of rolls.
6. Grab a (9 ounce) package of sliced black forest deli ham and lay it out evenly over the bottom layer of rolls.
7. Cover with 6 slices of swiss cheese.
8. Carefully place the top layer of rolls over the ham and cheese.
9. Spray a 9x13 pan with cooking spray and carefully place the rolls inside. Cover with foil and bake for 15-20 minutes, or until the cheese has melted and rolls are heated through.
10. Use a serrated knife to carefully cut the rolls away from each other. Serve immediately and enjoy!