Preheat the oven to 350 degrees. Slice the bread at 1-inch intervals, but don't slice all the way through the bottom. Mix the mayo, onion powder, garlic powder, parsley, basil, oregano, thyme, and the pepperoncini brine together. Spread this mixture down in between the sliced parts of the bread. Alternating the cheese varieties, shove a slice of cheese into each cut. Then alternating the salami varieties, shove about five slices into every other cut. Shove the pepperoncini slices and red onion slices into the remaining cuts, meaning the cuts with no salami in it. Wrap the whole thing tightly with foil and bake about 25-30 minutes or until the outsides are a little crispy and the cheese is all melted.
