Chicken and rosewater biryani

Name: Chicken and rosewater biryani
Ingredients: 250ml/9fl oz natural yogurt; 6 garlic cloves, finely crushed; 6cm/2½in (30g/1oz) piece ginger, finely grated; 3 green chillies, finely chopped, with seeds; 1 tsp Kashmiri chilli powder; 1 tsp ground coriander; ½ tsp ground turmeric; 500g/1lb 2oz skinless, boneless chicken thighs, cut in half; 300ml/10fl oz vegetable oil; 3 medium onions, thinly sliced; 10 whole cloves; 6cm/2½in piece cinnamon stick; 5 green cardamom pods, bruised with a rolling pin; 2 Indian bay leaves; 1 tsp cumin seeds; 2 medium tomatoes, chopped; 1 tsp salt; 600g/1lb 5oz basmati rice, soaked in cold water for an hour; 1 tsp salt per 1 litre/1¾ pint of cooking water; 100g/3½fl oz ghee; pinch saffron soaked in 4 tbsp warm milk for 15 minutes; 2 tsp rosewater; 20g/½oz cashew nuts and 20g/½oz shelled pistachios, dry-roasted in a hot pan until golden-brown; raita, to serve