Gather all ingredients and place the bread on a cutting board.
Starting with the ham, add a layer of meat, then alternate with a layer of cheese, overlapping the slices in each layer. Continue until each of the meats and cheeses until all of them have been used, distributing each meat and each cheese on the sandwich in a single layer.
Then scatter a layer of red onions, followed by the tomatoes.
Add a liberal amount of freshly ground pepper, then the lettuce.
Sprinkle a generous amount of the Italian dressing on the second half of the bread, then position it atop the sandwich.
If you’re serving the U-Boat as an appetizer, use the picks to secure it in sections, about 1 1/2 inches apart. If it is a main course, cut the U-Boat in quarters and spear each section with a pick.