Preheat the oven to 375°F (190°C).
In a large mixing bowl, whisk together the mayonnaise, red wine vinegar, pepperoncini brine, minced garlic, dried oregano, red pepper flakes, and grated parmesan cheese until smooth.
Add the shredded iceberg lettuce, thinly sliced red onion, and chopped pepperoncini to the dressing bowl. Toss thoroughly until the vegetables are completely coated in the creamy dressing.
Slice the bread loaf or hoagie rolls in half lengthwise and arrange the halves on a baking sheet.
Layer the salami, pepperoni, and ham onto the bottom half of the bread. Place the provolone cheese slices over the meat and on the top half of the bread.
Toast the sandwich in the oven for 5 to 7 minutes until the cheese is fully melted and the bread is golden brown.
Remove from the oven and place the tomato slices on top of the melted cheese. Season the tomatoes with a pinch of salt and black pepper.
Heap the prepared grinder salad onto the bottom half of the sandwich over the meat and tomatoes.
Close the sandwich, press down gently, and slice into individual servings before serving immediately.