||Preheat the oven to 180°C. Brush lamb shanks with a little oil.
||Heat a large frypan over a moderately-high heat. Brown the lamb shanks well on all sides. Remove and place them in a small roasting dish or large casserole dish.
||Reduce heat in pan and add a little extra oil, add the curry paste, cook stirring for 1 minute. Add the stock and coconut milk. Stir until the mixture boils.
||Pour over the lamb shanks. Add the sweet potato. Cover the dish tightly with its lid or foil, place in the oven.
||Cook for 1½-2 hours or until the lamb shanks are very tender. Add the vegetables, fish sauce and sugar in the last 30 minutes of cooking. Add a little water if needed.
||Cooktop method: Place the browned lamb shanks and other ingredients in a heavy-based pot. Partially cover, keep the heat low. Simmer until the meat is very tender.
||Stir occasionally; add water if needed during the cooking time to keep ingredients well covered.