Cut the ciabatta in half and spread a small amount of the Philadelphia evenly on each piece. Layer the tomatoes on the bottom side of the bread followed by the salami. Spread another generous layer of Philadelphia over the meat followed by a layer of arugula salad. Top with a top slice of ciabatta.

Wrap each sandwich tightly with plastic wrap and place on a platter. When all the sandwiches are prepared, place the platter in the refrigerator. Put a heavy skillet on top of sandwiches to apply weight. Refrigerate at least 6 hours or ideally, overnight.

When ready to serve, remove from plastic wrap and cut the sandwiches into 6-7 cm big pieces. Serve immediately or if desired, you can wrap the pieces in baking paper to protect them if you eat them later.