For this recipe I kept the lamb on the bone, because it gives more flavour and just for the sheer enjoyment of picking the meat off... If you wanted to serve it to friends as something more elegant, feel free to use neck of lamb without the bone.
Trim any excess thick lumps of fat off the meat. (Reserve the fat for later.) Add the lamb to a large bowl with all the spices. Rub them into the meat, cover the bowl in cling film and put in the fridge to marinate for 4 hours.
Pre-heat the oven to 150 C / Gas 2.
Put a large frying pan over a high heat and add the reserved fat to the pan. After a few minutes the natural fat oil will start to render out. Use this oil, and a dash of any extra oil to brown the meat on all sides. Once the meat is browned, remove from the pan and set aside.
Roughly chop the onion and sweat over a medium heat in the oil. When soft add the sweet potato and garlic and cook for a further few minutes.
Add the lamb, sweet potato mixture, tomatoes, honey, sultanas, lemon juice, zest and stock to a casserole dish. Bring to the boil over the stove. Then cover with a lid and put the tagine in the oven to cook for 2 1/2 hrs.
Remove from the oven, skim off any excess fat from the top. Serve with rice or couscous and fresh pomegranate seeds sprinkled over top.