In a large bowl, combine chicken with turmeric, Kashmiri chilli powder, lemon juice, ginger-garlic paste, and salt. Mix well, cover and set aside while you prepare the masala.

Heat a pan over medium flame and dry roast the red chillies, coriander seeds, peppercorns, fennel seeds, cumin, cardamoms, cinnamon, cloves, star anise, and stone flower until fragrant. Stir constantly to prevent burning. Transfer to a plate and let cool.

In the same pan, heat sesame oil. Add grated coconut, one sprig of curry leaves, and poppy seeds. Roast until the coconut turns golden brown.

First grind the roasted spices coarsely, then add the coconut mixture. Blend into a smooth paste, adding water as needed.

Heat oil in a heavy-bottomed pan or wok. Add bay leaves and the remaining curry leaves. Sauté for a few seconds.

Add chopped onions and cook for 6-7 minutes until light golden.

Add the marinated chicken. Stir-fry on high heat for 4-5 minutes, until the chicken changes colour.

Mix in tomatoes, Kashmiri chilli powder, and salt. Cook until the tomatoes soften and the oil begins to separate. Add a splash of water if needed.

Stir in the Chettinad masala paste. Pour hot water as required for the gravy.

Lower the heat, cover and cook until the chicken is tender and fully through.

Finish with chopped coriander leaves. Taste and adjust seasoning. If the gravy is thin, cook uncovered on high heat to thicken slightly. Note: It will thicken further as it cools.