Put the raisins, olives, shallot, vinegar, and oil in the bowl of a food processor. Puree until well combined. Transfer the olive mixture to a bowl, cover with plastic wrap and set aside for at least 1 hour or up to 2 days before using.
Open the bread like a book and spread each side with the mayonnaise and mustard. Lay 2 slices of ham and 2 slices of roast pork on 1 side of the roll. Top with 2 slices of cheese. Spread 1 to 2 tablespoons of the olive-raisin relish over the cheese. Bring the tops and bottoms of the sandwich together.
Wrap 4 bricks in aluminum foil and place in a 500 degree F oven for 15 minutes.
Melt the butter in a large skillet or griddle pan over medium heat (if your skillet isn't large enough you may need to cook the sandwiches in 2 batches). Place the sandwiches in the skillet and press down with the hot bricks for 3 to 5 minutes until the cheese is melted and the bread is flat and browned.