1. Wash and soak the rice for 20 minutes in cold water.
2. Mix all the ingredients for the marinade, add to the chicken thighs and set aside for 15-30 minutes. Meanwhile soak the saffron in warm milk, then mix in the ghee and rosewater after 3-5 minutes.
3. Put the chicken and marinade into a casserole dish, and bring to a simmer over a low heat. Simmer for 20 minutes until the chicken is tender.
4. Pour about 1½ litres of water into a saucepan, add the whole spices and salt and bring to the boil. Reduce the heat and simmer for 5 minutes or so. Now add the drained soaked rice and boil for about 8-9 minutes.
5. The rice should be 80-85% cooked. Drain the rice and layer over the marinated cooked chicken.
6. Sprinkle with some chopped mint and coriander, pour over the soaked saffron mix then cover the casserole with a lid. You may wish to seal the lid using some dough to create a pressure-cooking effect.
7. Now put the casserole on a low heat for 5-7 minutes until steam starts escaping from the lid, then remove from the heat.
8. To make the raita, put the cucumber and remaining ingredients in a large mixing bowl and mix them thoroughly. The raita should be not be too thick or thin in consistency. Leave it in the fridge for about 20 minutes and served chilled.
9. Leave the casserole aside to rest for 5 minutes after taking it off the heat.
10. Serve with the cucumber raita.