A Tagine is both an cooking vessel and the dish it's prepared in, originating in Africa. The conical shape of a tagine helps to baste the dish as it cooks. If you happen to have a tagine, that's great, but the dish works just as well in a medium or large covered pan. There are many variations on the dish, but in my family we like to use chicken thighs (with skin and on the bone, since they do well with the long cooking time). We've also done it with carrot in place of the sweet potatoes, and you can vary the fruit. Sometimes we do golden raisins and dried apricot in place of the dates. The chile-ginger-cinnamon broth is sweet, spicy, and delicious. The sugared walnuts and yogurt are for serving. Serve over cous-cous.