SweetWillie- This is a huge debate among Philadelphians (Where to get the best steak). Personally, I'm a big fan of Jim's Steaks on South Street. Also, Steak and Hoagie Works in the NE part of Philly makes one of the best.
What is in a steak? Anything you want. But yes, typically it's a slice or broken beef and cheese. I'm a big fan of the pizza steak- beef, sauce, and provolone cheese. Also, steaks come in chicken too. These are also equally delicious (chicken and american cheese). Try it with bacon for an added heart-attack.
Yes, these steaks are very high in calories- but worth it to eat once in awhile (not every day).