Special equipment: a straight-sided 3-quart tall glass bowl or four 16-ounce wide-mouth glass jars with lids
Using a 3-quart tall glass bowl for 1 large salad or four 16-ounce wide-mouth glass jars for 4 individual salads, make the first layer with half the lettuce. Follow with layers of the olives, salami, provolone, the remaining lettuce, then the bell peppers. Finish with the croutons and cucumber, and sprinkle the top with pepperoncini. (The salad can be put together, covered and refrigerated for up to 2 hours before serving.)
If making 1 salad, just before serving, transfer it to a large bowl and toss with the vinegar, oil, oregano, 1/2 teaspoon salt and a few grinds of pepper. If making 4, whisk the vinegar, oil, oregano, 1/2 teaspoon salt and a few grinds of pepper in a small bowl; add dressing to each jar, cover with the lid and shake to coat.
To achieve pretty, defined layers, be sure to layer more on the sides. It's OK if there isn't enough of an ingredient to fill the middle.