On a large cutting board, stack lettuce, sliced onion, sliced tomatoes, pepperoccini, salami, capicola, prosciutto, and cheese.
Using a sharp knife, chop everything into small, bite-sized pieces.
Top with mayo, olive oil, red wine vinegar, oregano, salt, and pepper and mix together (you can continue to do this on the cutting board or put everything in a bowl to combine).
Evenly distribute into the 6 small sub rolls and enjoy!