This isn't the shaved-meat-roasting-on-a-spit kind of shawarma. But by cooking the chicken in your slow cooker, you can still get that irresistibly tender texture and lightly toast it under the broiler at the end. The recipe calls for a whole chicken, flavored with a bevy of spices for a meal that will satisfy the whole family (or serve as your delicious next day's leftovers).