If the 6-foot roll is not already split, using a long serrated knife, slice lengthwise about 3/4 of the way through so the halves stay attached. Open the roll and press lightly to flatten slightly so fillings sit evenly.

Spread mayonnaise evenly on the bottom half of the roll (use most of the 1 cup), and spread Dijon mustard on the top half (use about half of the 1/2 cup). Reserve remaining mayo and mustard for guests who want extra.

Drizzle the interior of the roll with half of the olive oil (about 1/4 cup) and half of the red wine vinegar (about 2 tbsp) distributed evenly along the length. Sprinkle 1 tsp kosher salt, 1 tsp black pepper, and 1 tbsp dried oregano evenly along the length over the oil and vinegar.

Layer shredded iceberg lettuce evenly along the length of the roll (about 6 cups total). Arrange tomato slices on top of the lettuce in a single overlapping row; sprinkle tomatoes with 1 tsp kosher salt and 1 tsp freshly ground black pepper.

Distribute thinly sliced red onion, pickles, and pepperoncini evenly along the sandwich length in separate bands or mixed as preferred.

Meats & Cheeses

Create meat layers in sections so the sandwich is balanced when sliced. From left to right (or in repeated patterns), lay down 1–1.5 inches of Genoa salami slices in an overlapping fashion to create a continuous layer across the bread length. Repeat with capicola, mortadella, and smoked ham so there are contiguous meat zones. Use all the meat, distributing thickness evenly so each bite has variety.

Top each meat zone with provolone slices so the cheese overlaps slightly; place mozzarella slices in any zones where a milder cheese is desired. Use all the cheese, distributing evenly.

After cheeses are placed, drizzle the remaining olive oil (about 2 tbsp) and red wine vinegar (about 2 tbsp) evenly along the length. Sprinkle remaining dried oregano evenly, followed by grated parmesan if using. Add fresh basil leaves in pockets where you want bright herb notes.

Seasonings & Garnish

Taste one area as you assemble (small piece of meat + cheese + tomato + dressing) and adjust seasoning if needed: add extra salt, pepper, or oregano to balance flavors.

Close the top half of the roll gently. Using a long serrated knife or string, slice the 6-foot sub into portions for serving — common sizes: 6-inch (12 portions), 12-inch (6 portions), or other desired lengths. If serving immediately, press lightly to compact and transfer to serving board. If making ahead, wrap tightly in plastic wrap and refrigerate up to 6 hours; for longer storage, place in airtight containers to avoid sogginess.

Serve with extra pepperoncini, pickle spears, and small bowls of mustard and mayonnaise for guests to add more. Provide a small bowl of extra red wine vinegar and olive oil and extra oregano for sprinkling.