Depends on where you get one. Try Jims on South street.

www.chickiesandpetes.com/
I lived in Philly all my younger life.  There are cheese steak places and there are great places.  If you look for cheese steaks, watch to see the amount of meat on them, some are great and some are weak.  The cheese that some use now is canned cheese WIZZ, that makes my stomach turn.  Real cheese on real steak is my thing.  If you want a great place to eat out with a special person, "chickies and petes" is my best.  If you see Rita's Water Ice, stop for it.

Pats King of Steaks is the only cheese steak in town that doesn't make me sick.  Don't know why...but I have tried them all and this is the one...with cheese wiz and all.  Love em!