for the shawarma:
* You can make ahead to this point, and let it marinade up to overnight, or you can bake it right away (it makes little difference). If you can’t find boneless skinless chicken thighs, you can debone them yourself, but make sure you buy enough extra to make up for the loss of weight (they should weigh 3 pounds after deboning them).
** You can even make the whole dish ahead up to this point. Cook and slice the shawarma the day before you plan to serve, reserve the juices, and then sear at the last minute. The fat will solidify in the fridge overnight, and the juices will gel, but you can use it just like butter the next day (throw it in the pan and let it melt).