In a small bowl or jar, combine the red wine vinegar, olive oil, Dijon mustard, minced garlic, dried oregano, red pepper flakes (if using), salt, and black pepper. Whisk vigorously or shake well until fully emulsified. Set aside.

Lay out your romaine lettuce on a large cutting board. Using a sharp chef's knife, finely chop the lettuce into small, bite-sized pieces. Transfer to a very large mixing bowl.

Next, stack the provolone cheese, genoa salami, pepperoni, and deli ham slices. Using the same knife, finely dice all the meats and cheese into small, uniform pieces, similar in size to the chopped lettuce. Add them to the mixing bowl with the lettuce.

Add the finely minced red onion, drained and chopped banana peppers (or pepperoncini), quartered cherry tomatoes, and fresh parsley (if using) to the mixing bowl.

Pour about half of the prepared tangy vinaigrette over the chopped ingredients in the large bowl. Using two spatulas or large spoons, thoroughly toss all the ingredients until everything is well combined and evenly coated with the dressing. Add more vinaigrette to your liking, ensuring the mixture is moist but not soggy.

Taste the mixture and adjust seasonings if necessary. You might want more salt, pepper, or a pinch more red pepper flakes for extra kick.

To serve, open each hoagie roll and scoop a generous amount of the chopped Italian sandwich mixture into each roll. Press down gently to compact the filling.

Serve immediately. For an extra touch, you can lightly toast the hoagie rolls before filling, if desired.