For the chicken, pour the yoghurt into a shallow dish. Add all the spices, root ginger, lemon juice and Salt and stir well. Add the chicken, cover and leave to marinade for a minimum of 4-5 hours in the refrigerator, or for best results overnight.
Something else to do in advance is to soak your rice. Place the rice in a bowl of cold water and leave to soak for a few hours. Drain and rinse thoroughly under cold water to remove all traces of starch and then set aside.
When you are ready to cook your biryani, pre-heat the oven to 200°C, 400°F, Gas Mark 6.
Heat the butter in a frying pan and fry the onions, Cumin Seeds, Cloves, Cinnamon, Star Anise and Cardamom Pods over a medium-heat for 10-12 minutes, until softened and turning golden brown. Season well, then stir in the peas, Garlic, Chilli and Turmeric and fry for a further 2 minutes.
Meanwhile, add the Saffron to the milk and warm through in a small saucepan to infuse.
To assemble the dish, pour half of the soaked rice into a large casserole dish. Top with half of the marinaded chicken and half of the onion mixture. Repeat this with the remaining ingredients. Add the water to the milk and pour over the ingredients, ensuring that the rice is covered with the liquid. Add the Bay Leaves and cover with a tight-fitting lid.
Cook in the oven for about 1 hour 15 minutes – 20 minutes, or until the rice is tender and the chicken is cooked through.