It looks like the origin of the classic Tony Stark shawarma scene in The Avengers can be found in the early days of Buffy the Vampire Slayer. In a special feature included in the Buffy Chosen Collection, Joss Whedon explains that the reason that Nicholas Brendon (Xander) is on the show is because he inserted a shawarma reference into his audition. Whedon explained,
We brought him in, we weren't sure, it wasn't a slam dunk, it hardly ever is … and Nicky just tore the place apart, was just weird. We hadn't seen it before. Afterwards, he was like, 'Does anybody feel like shawarma? I feel like some shawarma!' And I was like, 'This guy speaks to me!' That was it. I knew there was no other Xander.
He continues saying,
If you had said falafel, you might not be here.
That's pretty awesome! You can watch the video below! I guess may Brendon should have received a special thanks in the credits or something for being so spontaneous and coming up with a future Avengers scene. I think it's about time I watch Buffy again. What do you think of the origin of the shawarma scene?