Preheat the broiler to 400° F. For easy cleanup, line a large, rimmed baking sheet with parchment paper.
Slice the Italian loaf in half lengthwise and place on the baking sheet.
On the bottom half of the bread, evenly layer and distribute all the deli meats.
On the top half of the bread, evenly layer and distribute the cheese slices.
Place the baking sheet in the oven and broil for 3-5 minutes or until the cheese has melted and the bread has become nice and crispy.
Meanwhile, in a medium bowl, make the salad mixture by whisking the mayonnaise, Dijon mustard, red wine vinegar, pickle relish, and Italian seasoning together. Season to taste with a small pinch of salt and black pepper.
Add banana peppers, red onion, and iceberg lettuce. Toss to combine.
Remove the bread from the oven.
Pile on the salad mixture, then top with tomato slices and grated parmesan cheese.
Slice into 4 hearty sandwiches and enjoy!