Pour about 4 tablespoons of vegetable oil into a large saucepan or casserole dish on a medium heat. Add the lamb and fry on all sides for 3-4 minutes, stirring frequently.
Add the remaining oil, if necessary, then tip in the onions, garlic and spices and add seasoning. Cook for 15 minutes stirring occasionally, until the onions are soft and beginning to brown.
Add the coconut milk, stock and tomatoes, stir well and reduce the heat to low. Gently simmer, uncovered and stirring regularly, for 11/4 – 2 hours or until the meat is meltingly tender.
When the lamb is cooked, stir in the lime juice and chopped mint, taste for seasoning and then serve immediately with some lime wedges.