Preheat the oven to 375°F.
Carefully slice each hoagie roll lengthwise, ensuring not to cut all the way through so the rolls remain hinged.
Layer the ham, salami, roast beef (or cooked ground beef), and pepperoni inside each hoagie roll.
Place two slices of cheese on top of the meats in each sandwich. If desired, add banana peppers and sautéed onions.
Arrange the filled sandwiches on a baking sheet lined with parchment paper.
Brush the tops of the rolls with melted butter and sprinkle evenly with Italian seasoning.
Loosely cover the sandwiches with foil and bake for 10-15 minutes, or until the cheese is melted and the fillings are heated through.
Uncover the sandwiches and bake for an additional 2-3 minutes until the tops of the rolls are golden and crisp.
Serve hot with chips, olives, or a fresh side salad as desired.