1. Prepare pastrami, turkey, ham and cheese.
2. Cut the loaf of bread almost in half horizontally (leave some space at the end).
3. Layer one of the cut sides of baguette with half of lettuce, then top the lettuce with half of the diced tomatoes, spread some mayonnaise on top of the tomatoes and add half of the onion slices.
4. Add layers of turkey, pastrami, cheese and ham.
5. Top the ham with the rest of the tomatoes, onions and spread some mayonnaise on top of onions.
6. Add a layer of lettuce and press the sub slightly with your hands.
7. Cut into serving-size pieces and serve.