Had a beef shawarma at Sarah's last night. We drove by on the way to a concert. I haven't had one from there in a few months, and the shawarma was better than ever.
I don't know how they do this, but the beef was tender and crispy at the same time. And the other fillings are superb too. First some humous and garlic sauce on the pita. Then hot sauce - theirs is a really hot chili oil with lots of chili gunk on the bottom - if you want it super hot like i do - they put on the gunk at the bottom of the oil and not just the oil itself - amazing. Then lettuce, tomato, pickled turnip, onions, and parsley, then the beef, then tahina dressing. They wrap it up and put it between a press to warm/crisp the pita.
A perfect shawarma.