Spray a standard (12 cup) bundt pan with baker's spray and set it aside.
Remove the 2 (1-pound) loaves of the frozen white bread dough and thaw according to package directions. I thawed mine on the counter, and it took 1½ to 2 hours.
Once thawed, you will cut one of the bread loaves in half, giving you a total of 1½ pounds of thawed white bread dough that you will use. You can discard the extra piece of thawed dough or do something else with it.
Shape the two thawed pieces (the 1-pound and one of the ½-pound pieces) of the white bread dough into a long rope shape about 16 inches long. You will need to pinch the two pieces together to form a ring. Place the ring into the bottom of the prepared bundt pan. Make sure that the ring is as symmetrical as possible so that your baked sub ring is evenly shaped.
Cover the bundt pan with a piece of plastic wrap and allow the dough to rise on the counter for 3 to 6 hours, or according to your package directions, so that your dough doubles in size. This time varies greatly due to the temperature in your home. If it is very cool or very warm, the dough will rise accordingly.
Once your dough has doubled in size, preheat the oven to 375°F. Bake for 25 to 30 minutes or until golden brown. Allow the baked bread to cool in the pan for 10 minutes, then invert it out onto a cooling rack to cool completely.
Once completely cool, slice your bundt-shaped bread loaf in half horizontally and place it onto a serving tray.
Remove the top half of your sub loaf and place it to the side. On the bottom half, start by layering the provolone cheese, overlapping the slices, to cover the entire circle loaf.
Next, you will place the tavern ham slices, folded in half and overlapping, to cover the provolone cheese slices. You will follow that with the mortadella, then the capicola, the genoa salami, and finally the sandwich pepperoni slices.
Carefully top the layers of meat with the shredded iceberg lettuce.
Separate the onion slices into individual rings, arrange them on top of the lettuce, and follow that with the tomato slices.
In a small mixing bowl, stir together the mayonnaise and yellow mustard. Generously spoon the sauce over the top of the vegetables and place the top of the bread that was set to the side onto the top of the party sub.
Slice your party sub into eight equal portions.