Joint the chicken, and simmer till tender in stock. Strain and reserve a teacup of the stock. Mince together finely, the coriander leaves, green chillis, garlic and ginger. Heat oil in a heavy pan and fry the onions, minced spices, garam masala and ground cummin, till golden. Beat the yoghurt and combine with the reserved stock, add to the pan and bring to the boil. Put in the chicken and cardamoms and simmer for a few minutes. Add cashew nuts and cook, stirring, till simmering point. Season with salt.
Note: Preparation time 15 minutes, Cooking time 1 hour IO minutes, To serve 4