Mix the yoghurt with the cayenne pepper, coriander, cumin, garlic, ginger, paprika and turmeric.
Trim the lamb of any fat and cut it into 5 cm (2 in) cubes. Put them into a nonstick saucepan with the onions, place the pan over a medium heat and stir until the contents begin to sizzle.
Add the yoghurt mixture, reduce the heat to low, cover and cook for about 30 minutes, stirring occasionally, until the lamb has released all its natural juices.
Remove the lid, increase the heat to medium and cook for 5-6 minutes, stirring frequently, until the sauce has reduced to a paste-like consistency.
Put a kettle on to boil. Add the tomato purée, some salt and 15 g (½ oz) of the butter to the lamb. Reduce the heat to low again and cook, uncovered, for 3-4 minutes, stirring frequently. Then add 350 ml (12 fl oz) of boiling water from the kettle, cover and simmer for 15 minutes.
In a small pan, melt the remaining butter over a low heat, add the bay leaves, cardamom, cinnamon and cloves and allow them to sizzle for 35-40 seconds. Add the nutmeg, stir once and pour the contents over the meat. Mix well, cover and cook for a further 10-12 minutes. Stir in the chopped mint and coriander and serve.
I made this for lunch today, it is absolutely divine! I found the consistency a bit runny so thickened it up with cornflour, but I was a bit heavy handed on the yoghurt so it goes without saying! Thank you very much for sharing. Will definitely be making this again. - 19 Feb 2012