Unfortunately not. There are recipes (NYT, serious eats, epicurious, etc.), and it’s not too hard to make at home.
The NYT recipe is actually for chicken shawarma, but there’s a discussion of white sauce with it, and a great suggestion by Sam Sifton, commenting on his own recipe, to add fried eggplant. You’d occasionally find a cart in NY that offered it as an option and I always took it.
