Dice the lamb and reserve. Heat the oil or ghee in a large frying pan, add the mustard seeds and fry for 30 seconds, or until they pop

Add the remaining spices and cook for 2 minutes, stirring, before adding the garlic, chillies, onions and aubergine. Cook, stirring, for a further 5 minutes, or until the vegetables are coated in the spices

Add the lamb and continue to fry for 5 - 8 minutes, or until sealed. Stir in the chopped tomatoes. Blend the tomato puree with the stock then pour into the pan

Bring to the boil, cover, reduce the heat and simmer for 45 - 50 minutes, or until the lamb is tender. Sprinkle with chopped coriander and serve with plenty of naan bread