I had to stop a Primanti Brothers for one of theirs.
It is in the warehouse district and supposedly the sandwich is made so that the working guys can eat a meal with one hand and push a hand truck with the other.
That means that when you order a sandwich you get it with fries and slaw on it.
My cousin was telling me that a local custom is to take an out-of- towner down there after midnight. (they are open 24 hours)
If they can get the guy to go in wearing a tie somebody from the kitchen wearing a bloody apron shows up and cuts it off with a cleaver. Sounds like fun if you are not the one with the tie.