Begin by marinating the chicken. In a large bowl, take the curry cut chicken pieces. Add in salt, turmeric powder, and lemon juice. Mix well and keep aside to marinate for about 30 minutes.
In the meantime, prepare the Chettinad masala. Heat 1 tbsp of sesame oil in a pan. Add in the coriander seeds, cumin seeds, and fennel seeds. Mix.
Add in the peppercorns, cloves, green cardamoms, black cardamom, and star anise. Mix well.
Add the cinnamon, mace, bay leaves, and stone flower. Saute until they crackle keeping the flame medium to low.
Add in whole red chillies with the stems removed. Saute for a minute. Remove to a plate and keep aside to cool.
In the same pan, roast the grated coconut until it browns. Remove to a plate and keep aside to cool.
When cooled, transfer the masalas and the coconut into a grinder jar. Add in garlic, ginger, tamarind paste, and fenugreek seeds. Add a bit of water. Blend into a smooth paste and keep aside.
Heat 2 tbsp of sesame oil in a pan. Add in chopped onions and 3 sprigs of curry leaves. Saute until the onions are browned.
Add in the marinated chicken and saute until it is seared.
Add in the chettinad masala paste. Add a bit of water and mix well. Cover it with a lid and let it simmer until the chicken pieces are cooked.
Check the salt and add more if required. You can adjust the gravy as per your taste. I prefer the semi dry version.
The Chicken Chettinad is ready to serve. Garnish with fried curry leaves and serve with Malabar parathas.