The only thing that makes this even remotely related to a cheesesteak is the fact that you’ve somehow managed to use the same animal. Roast beef does not a cheesesteak make.
Everything else isn’t even close.
On behalf of the city of Philadelphia, please remove all mention of “Philly” or “cheesesteak” from this recipe. Stick with the title you chose for your post, “grilled pepper jack and roast beef sandwich” (I’d throw the word pita in before sandwich just so it’s very clear that there’s no relation to Philly.) I’m serious.
Buttered pita makes this a deliciously crispy version of a Philly cheesesteak.
1. 2 tablespoons unsalted butter, softened
2. 4 thick, pocketless pitas, split
3. 2 tablespoons mayonnaise
4. 1/2 small red onion, thinly sliced
5. 8 ounces thinly sliced pepper Jack cheese
6. 8 ounces thinly sliced rare roast beef
See the whole recipe here
The only thing that...even remotely related to...cheesesteak...