Bake the loin filet in the oven according to the package directions. Let stand for 5 minutes covered with aluminum foil before slicing.
Meanwhile, halve the ciabatta rolls lengthwise and open flat.
Distribute the cheese slices among all of the ciabatta halves. Garnish the bottom halves with sliced pork, apple and arugula. Close the sandwiches.
Transfer the sandwiches to a large heated pan and place a weight (e.g. cast-iron pan) on top to flatten them slightly while cooking. Cook over medium heat for 7 to 8 minutes on each side or until the cheese melts and the bread is browned and crispy.
Slice each sandwich in two and serve with raw veggies.
Cooking on barbecue:
Cook the loin filet on the barbecue over medium-high heat for 15 to 17 minutes.
Reduce the barbecue to low heat.
Place the sandwiches on the grill and cook for 5 to 7 minutes on each side or until the cheese melts and the bread is browned and crispy.