Cooking the sausages on a griddle is the authentic Jersey Shore method for making these sandwiches. If you don’t have a griddle — or preferred grilled sausages which are also excellent — cook them on a charcoal or gas grill.Heat the olive oil in a large, deep skillet over medium heat. Add the garlic (if using) and cook just until it begins to turn golden, about one minute. Add the onions and cook, stirring often, until wilted, about five minutes. Add as many of the pepper strips as possible without overcrowding the pan. Continue adding more peppers as those in the pan wilt until all the peppers are added. Reduce the heat to low and season the peppers and onions lightly with salt. Continue cooking, stirring occasionally, until the vegetables are tender and browned, about 25 minutes. Season to taste with salt and pepper and keep warm. (The peppers and onions can be prepared up to a day and advance and reheated over low heat.)Heat a griddle over medium heat. Poke the sausages all over with a fork and cook them on the griddle, turning occasionally, until they are browned on all sides and almost fully cooked, about 15 minutes. Remove the sausages from the griddle and cut them lengthwise almost but not completely in half.) The sausages should then lay flat. Cook them on both sides until well browned, about five minutes. Divide the sausages among the hero rolls and pile the sandwiches high with peppers and onions.