01 -
Combine chopped green olives, black olives, giardiniera, roasted red peppers, and garlic in a medium bowl. Add olive oil, red wine vinegar, capers, black pepper, and celery salt. Mix thoroughly. Cover and refrigerate for at least 1 hour, up to one week.
02 -
Using a serrated knife, slice the bread loaf horizontally. Place both halves cut side-up. If the bread halves exceed 4 cm in height, remove some of the soft interior to create space for the fillings.
03 -
Evenly spread half of the olive salad with its oil onto the bottom bread half. Layer half of the mozzarella, all the salami, half of the provolone, all the mortadella, the remaining mozzarella, all the capicola, and the remaining provolone in this order.
04 -
Press the remaining olive salad with a spoon to release excess oil into a bowl, then evenly distribute the salad atop the layered cheese. Drizzle the cut side of the top bread with reserved olive oil. Close by placing the top bread half over the fillings.
05 -
Wrap the assembled sandwich tightly in aluminum foil. Place a heavy object, such as a Dutch oven, on top and allow it to rest at room temperature for 1 to 3 hours to compress and meld the flavors.
06 -
For toasted texture, heat oven to 190°C. Place the foil-wrapped sandwich directly onto the rack and bake until the bread is crisp, 10 to 20 minutes.
07 -
Remove foil. Cut the sandwich into wedges with a serrated knife. Serve immediately, with pickled pepperoncini or potato chips if desired.