A cheesesteak wit is not a recipe. It is half of a sentence spoken at a Philadelphia order window, and the sentence is the sandwich. "Wit" means with fried onions; the word that pairs with it is the cheese, named in the same breath, so a full order is two syllables that resolve the only two variables anyone argues about. The defining thing here is the onion decision and what it does on the steel: a handful of sliced onion cooked down soft and sweet on the same flat-top the beef is chopped on, then folded through the meat so it ends up inside the pile rather than scattered over it. That is the whole difference between a wit and a witout, and it is enough of a difference to have its own name at the counter.
The craft is the standard ninety seconds, with the onion timed into it. Thinly sliced beef is chopped and seared fast and hot so it stays pliable; the onion goes down early enough to soften and caramelize before the meat is folded over it, because raw onion thrown on late stays sharp and wet and breaks the texture. The cheese, whatever was named, is laid on while the pile is still on the griddle so it melts into the beef and onion together and binds the three into one mass. The long roll is a structural component, tender inside and crusted enough outside to carry a heavy, greasy, fused filling without tearing. The order itself is the craft as much as the cook: a clean two-word call keeps a fast line moving, and the onion is the part that decides whether the sandwich reads sweet and round or flat and direct.
The variations are the rest of the grammar that "wit" lives inside. Witout drops the onion and lets the cheese carry the sandwich alone. Whiz wit fixes the cheese as processed sauce and keeps the onion; provolone wit and American wit name a firmer or a flowing cheese against that same onion base. Each is its own order with its own logic, and each deserves its own article rather than being crowded in here.