Make the dressing. In a small bowl, whisk the mayonnaise, olive oil, red wine vinegar, pepperoncini brine, Parmesan, garlic, oregano, salt, black pepper, and red pepper flakes until smooth. It should be pourable like thick ranch. If it is too thick, whisk in 1 to 2 teaspoons water. Refrigerate until needed.

Chop the lettuce. Cut the iceberg in half through the core and cut out the core. Slice each half into thin strips, then cut the strips crosswise into pieces about 1/2 inch wide. Add to the large bowl.

Chop the deli meats. Stack the salami, pepperoni, and ham slices in small piles. Cut into 1/2-inch strips, then cut crosswise into pieces 1/2 inch or smaller. Add to the bowl.

Chop the provolone. Stack the provolone slices, cut into 1/4-inch strips, then cut crosswise into small dice. Add to the bowl.

Prep the vegetables. Quarter the tomatoes, finely dice the red onion, and chop the pepperoncini. Blot the tomatoes and pepperoncini on a paper towel so they do not thin the dressing. Add all three to the bowl.

Add the dressing. Pour in half of the dressing. Toss with tongs or two large spoons, lifting from the bottom of the bowl, for about 30 seconds until every piece looks glossy. Add more dressing 1 tablespoon at a time until the salad is coated but nothing pools at the bottom.

Taste and serve. Taste and adjust with black pepper, red pepper flakes, or a splash of pepperoncini brine. Serve right away while the lettuce is crisp.