Roll out one sheet of puff pastry to a 12 - 14 inch square. Brush lightly with mustard. Add one layer of proscuitto, then sprinkle with asiago or parmesan. Roll up and seal edge with an egg wash. Freeze rolls for approximately 1 hour or until firm enough to slice. Cut into small disks - about 1/4 inch thick and bake at 425 degrees for 10-15 minutes on parchment.
Note: disks can be frozen uncooked and baked in the future.