Slice the bagel. Place at least 2 tablespoons of the tapenade on each bagel slice, spreading it to the edges. You may need a little more or less. You want to really cover the bagel, this will keep it from becoming soggy.
Place the salami on top of the olive salad, then the pepperoni, followed by the ham slice.
Put a few slices of onion, if desired on top of the ham. Top with a slice of provolone cheese or another cheese if you prefer.
Cover with the bagel top and press down.
Wrap tightly with plastic wrap and refrigerate for a few hours to let the flavors meld . These can be made 24 hours in advance. These are very substantial sandwiches.