Slice bread in half, lengthwise. Spread one side with mayonnaise and the other with mustard.
Top the bottom half of the bread with a layer of each lettuce, swiss cheese, turkey, ham, and roast beef. On the top half, top with a layer of each tomatoes and Colby jack cheese (and more lettuce if desired). Flip the top half over on top of the bottom half of the sandwich.
Slice into individual portions. Serve with potato chips and pickles.
The amounts of ingredients needed will depend on the size of the loaf of bread. For longer loaves of bread, you will use a greater amount of the ingredients. Shorter loaves will require less.
Use thin-sliced meat from the deli counter. Lightly pile or drape the meat on the sandwich. This creates a nice bite and prevents the meat layer from being too dense.
Build the sandwich just before serving. This helps to maintain the texture of all of the individual ingredients. If making the sandwich ahead of time, to take on a picnic perhaps, it's best to leave wet toppings like tomatoes or pickles on the side. Then, when ready to serve, layer these items on the sandwich.
Due to the large, somewhat cumbersome size of this sandwich, I find it easier to cut the top and bottom halves into slices separately, then reassemble.
For a warm, toasted sandwich, build the sandwich with the spread, meats, and cheese. Wrap in foil and heat at 350 degrees for 15 minutes or until warm throughout. Then, open the sandwich to add the fixings, slice, and serve.