Clean the chicken pieces, make small slits on them and mix with salt, red chili powder, turmeric, ginger garlic paste and lemon juice in a mixing bowl. Let this marinate while you proceed with the rest of the steps.
Heat a wok or pot with high sides on the stove top. Add the whole spices - cinnamon, cloves, cardamom pods, peppercorns, fennel, coriander seeds, cumin for a couple of minutes until fragrant.
Add the grated coconut and heat, stirring regularly with a spatula. The coconut should turn light brown. Turn off the heat. Transfer all the iroasted ingredients into a blender jar (or coffee grinder).
Grind or blend together the roasted coconut and spices along with a couple tablespoons of water. It should form a semi-coasre paste.
In the same wok, on medium heat, add the vegetable oil and let it heat. Then add the onions followed by the bay leaves. leaves and onions.
Saute until the onions turn light brown. If the onions are sticking to the bottom of the wok, add a little water.
Now add the ground Chettinad masala, followed by chopped tomato, and curry leaves. Cook for a couple of minutes untill the tomatoes begis to soften.
Add the marinated chicken, stirring it well, so that the chicken is well coated with all the spices. Add 1 cup of water to the pan, cover it with a lid and let it cook on medium heat for 5-7 minutes.
Remove the lid, and continue cooking for a further 18-20 minutes until the chicken is cooked, and the water reduces. The gravy in the curry should be thick. Turn off the heat.
Prepare the tempering - heat the coconut oil in a small sauce pan. heat some coconut oil in a small saucepan, and once hot, add the mustard seeds. Once the seeds start to crackle, add curry leaves. Heat the curry leaves until aromatic, and turn off the heat. Drizzle this tempering over the chicken curry and serve.
Garnish with the chopped coriander and serve with basmati rice or malabar parottas.