Cut cheese into slices and add a layer to your bread. Slice your Grand Cru cheese into little slivers as thin as you can get them to make for easier melting. Then lay one layer of cheese on your bottom piece of bread.
Add a layer of prosciutto on top of the cheese layer. I like to add 2 pieces to make it a little thicker.
Scoop some cranberry sauce right on top of the prosciutto layer. It is okay if it is oozing over the sides.
Over medium/low heat, grill until you see your cheese melting. Then flip and do the same to the other side.