Preheat oven to 350.
Cut rolls in half. (If they are connected, slice through the middle with one cut simultaneously to have one bottom and one top. You will cut them apart individually later)
Place bottom half of rolls in cooking pan or 9x13 dish.
In a medium saucepan, combine butter, brown sugar, Worcestershire sauce, and mustard.
Bring to a boil over medium heat.
Remove from heat.
Using a pastry brush, brush inside of rolls until one layer of sauce coats across the inside of the bread.
Place 6 slices of cheese on top of bottom half of rolls.
Cover with ham, layering evenly.
Place 6 more slices of cheese on top of ham.
Brush inside of the top of rolls with butter mixture. Cover with tops of rolls.
Brush tops of rolls with remaining sauce.
Sprinkle with poppy seeds if desired.
Cover loosely with foil.
Bake at 350 for 15 minutes on the middle rack of the oven.
If you are cooking multiple pans, cover with foil and bake for 15 minutes.
Uncover and bake 5 more minutes.
Cut rolls apart and serve hot.
Enjoy the ooey, gooey yumminess.