To make Chettinad masala paste--> Take a pan d 1 tsp of oil and add the dry ingredients first and roast well, Then add the chopped onions, tomato saute well for a few mins. Add 1/2 cup of water and blend well into a smooth paste. Keep it aside.
To make Coconut paste -->Take 1/4 cup grated coconut , fennel seeds, Cashews,1/4 cup of water in the blender and Blend well into a fine paste.
Heat a pan to add 2 tbsp of Gingerly oil, 1/2 tsp Mustard seeds, 1 tsp Cumin seeds,1 No Bay Leaf,1 Cinnamon (1inch), 2 Cloves,1 Cardamom, curry leaves and Then, add the chopped onion, 1 tsp salt, roast well.
Add turmeric powder, chili powder, and mix well. Then, add Ginger-Garlic paste and saute well until raw smell goes away.
Add the cleaned chicken and mix well. Add the grounded Chettinad masala paste, salt req, and mix well. Add ½ cup of water, mix and allow it to cook for 10 min.
Now, add Coconut milk paste and mix well, Add salt if required, Mix well and cook for 7-10 min.
Garnish it with few coriander leaves and serve it hot with Plain Rice, Dosa , Idly, Parotta, roti, Idiyappam,Poori, best side dish for all Chicken Biriyani.