Cut all 12 rolls in half. Place roll bottoms in 9x13 pan.
Place equal amounts of ham on each roll bottom. Top with a slice of Gruyere.
On each of the roll tops spread a generous amount of the Philadelphia chive and onion cream cheese. Return the tops to the bottoms...making a sandwich.
In a separate bowl mix together the butter, worcestershire sauce, onion flakes and Parmesan cheese. Pour over your sandwiches and let it sit for at least 20 minutes (you can make these ahead of time and allow to sit in fridge overnight).
Place sandwiches, covered in foil, into a preheated 350 degree oven. Bake for 20 minutes or until warmed through.