With a sharp knife, make 1/4-inch to 1/2-inch-deep gashes on all sides of lamb in a crisscross pattern. Place the lamb in a plastic bag. Combine yogurt, lime juice, ginger, garlic, salt and pepper in a bowl. Pour the yogurt mixture over the lamb, turning to cover. Marinate in the refrigerator for at least 2 hours or overnight.
Preheat oven to 450 °F. Place the lamb on a lightly oiled rack in a roasting pan. Combine coriander, cayenne, cinnamon, cloves and cardamom in a small bowl. Sprinkle evenly over the lamb.
Roast the lamb for 15 minutes. Reduce heat to 325 ° and continue roasting until a meat thermometer registers 140 °F for medium-rare, 55 to 60 minutes. Let stand for 10 minutes before carving.
Meanwhile, make Fresh Mango Chutney to serve with the lamb.