Wash the rice three times, then soak for 30 minutes, wash again and soak for another 30 minutes. Wash once more before cooking
Reserve one bay leaf, half a cinnamon stick, 2 cloves and 3 peppercorns for the water you will cook the rice in later
Put 2 tbsp of oil in a pan and add some of the whole spices (a bay leaf, 2 cloves, a peppercorn, 1 star anise, ½ cinnamon)
Cook the chicken in the pan with the whole spices until just cooked and coloured. Season the chicken when it is cooked and set aside to cool
In a frying pan add 1 tbsp of oil, fry the onions until golden and then drain on kitchen paper
In the same frying pan add 1 tbsp of oil and then fry the potatoes cubes and drain on kitchen paper
When the chicken has cooled completely, add the natural yoghurt and half the fried onions, mix well and set aside
In a large pan heat 1 tbsp of oil and the butter and add all the remaining whole spices, chillies, ginger, garlic, tomatoes and make a thick gravy sauce. Add the cumin, garam masala, coriander powder and turmeric. Taste and adjust as necessary
Keep cooking the gravy on a medium heat until the oil separates 45- 50 min). Add more butter if it looks dry (or a drop of water) or a little pasata to thicken if necessary, keep and eye on it and don’t let it stick
Add the marinated chicken to the gravy and mix well
In a separate pan boil water adding the reserved spices. Add the rice, bring back to the boil and cook the rice for 3 minutes and drain
Now to put it all together. A layer of meat, then rice, then more meat and finally top with rice. Add the saffron onto the top layer and spread evenly. Sprinkle the rest of the fried onions and add a little butter
Cover with a tight lid and steam on a very low heat for 10 minutes, then leave for 5 minutes without removing the lid
Serve immediately by carefully spooning a mix of rice and meat onto a plate and garnish with some fresh coriander leaves