There has always been the debate over the type of cheese used on a Philly Cheese Steak. The three popular cheeses are Provolone, Swiss, White American, and the one I would never use - Cheez Whiz. Cheez Whiz was introduced because of convenience. I would say that the Provolone is my favorite cheese to use. I put slices on the bottom of the toasted roll and on top of the steak, onions, and peppers.
½ red bell pepper
½ yellow bell pepper
Add peppers and sauté another 15 minutes, stirring often.