Mix all the spices and sprinkle half of the spice rub over the lamb. Massage it into the meat, cover and refrigerate overnight.
Preheat the oven to 160°C.
Heat a large casserole and add the olive oil, lamb, remaining spice mixture, onion and garlic and sauté for 5 minutes until golden brown. Add the remaining ingredients and bring to a simmer. Fit with lid and place the casserole in the oven for 4 to 5 hours until the lamb is tender.
Garnish with chopped parsley and coriander and serve with basmati rice.