I don't really use measured amounts, since you can easily use as much or as little as you want of each ingredient. Just use this as a basis for these sandwiches, which happen to be one of my son's favorite.
hoagie buns, sliced
bulk hot Italian sausage, browned and drained
thinly sliced Mozzarella cheese
mild banana peppers, thinly sliced, optional
On the bottom of each hoagie bun, layer the ingredients in the order given. Replace the tops of the buns and wrap individually in foil and place on a baking sheet. Bake 425 degrees for 12 - 15 minutes, or until cheese is melted.