In a small bowl, mix together the minced garlic, cumin, coriander, paprika, turmeric, cinnamon, black pepper, salt, olive oil, and lemon juice to form a paste.
Rub the spice paste all over the lamb, making sure to cover it evenly.
Cover the lamb with plastic wrap or place it in a large resealable bag, and refrigerate for at least 4 hours, preferably overnight to allow the flavors to penetrate.
Preheat your oven to 350°F (175°C) if you are using an oven. Alternatively, you can prepare a grill or barbecue for cooking the lamb.
If using an oven, place the marinated lamb on a roasting rack set inside a baking tray.
Oven: Roast the lamb in the preheated oven for about 2-3 hours, or until the meat is tender and falls off the bone. Baste occasionally with the drippings from the pan.
Grill/Barbecue: Grill the lamb over medium heat, turning occasionally, until the meat is tender and has a nice char on the outside. This should take about 1.5 to 2 hours.
Remove the lamb from the oven or grill and let it rest for about 15-20 minutes before carving.
Garnish with chopped parsley and serve with lemon wedges.
Enjoy your meal!