Originally Posted by Schmoke
A 'proper' cheesesteak uses Cheez Whiz. Provolone may make it a much better sammitch (and it does for many), but Cheez Whiz is needed for authenticity. Similarly, if you don't use that Amoroso bread, it's not authentic.
The original poster requested "authentic". If he meant 'best tasting', this thread is most helpful.
Similar to the oft-debated Chicago style pizza -- cornmeal in the dough or not? NO, if you want authentic. YES, if you want something that many believe improves on the original.
The topic of cheese on an "authentic" Philly cheesesteak gets argued about, a lot. I personally agree with aawa that there are at least two, possibly three "authentic" cheeses. My family ate cheesesteaks with provolone. I don't remember EVER eating one with Cheese Whiz.