For the marinade, heat a small frying pan, once hot add the coriander seeds, fenugreek seeds, mustard seeds, cumin seeds, fennel seeds, black peppercorns, cinnamon stick, cloves and cardamom seeds. Once they start to pop add them to a spice grinder or pestle and mortar and blend until you have a fine powder.
Place the ground spices, turmeric powder and bay leaves in a small bowl and mix in the oil. Spread half the marinade all over the chicken and leave to marinate for 24 hours.
To cook the chicken, preheat the oven to 180C/350F/Gas 4.
Roast the chicken for 1-1½ hours, depending on the size of your chicken. To check if the chicken is ready pierce the chicken by the leg and thigh, if the juices run clear the chicken is cooked. Set aside to rest.
Meanwhile, for the curry, heat a large frying pan and add the oil. Once hot, add the remaining marinade paste and cook for a few minutes. Add the onion, garlic, chilli, ginger, curry leaves and tamarind paste and cook for a further 2-3 minutes. Add the tomatoes and stock and cook for 10-15 minutes.
Cut the chicken into eight portions. Add the chicken to the sauce and cook for 3-4 minutes, or until the chicken is hot.
For the pilau rice, heat the oil in a large saucepan and, once hot, add the onion. Cook until the onions are golden-brown, this will take approximately 10 minutes.
Stir in the cardamom, cinnamon and cloves. Add the rice and stir to coat in the onion spice mix. Add 600ml/20fl oz water and bring to the boil, reduce the heat to low and cover with a lid. Cook for 15 minutes then turn off the heat, leaving the lid on, and leave to steam for another 15 minutes.
To serve, place the curry in shallow serving bowls and sprinkle over the chopped coriander. Serve the rice in a separate bowl.