Marinate the Chicken pieces with yogurt, spices and ginger garlic paste. Keep it airtight marinated either overnight refrigerated or atleast for 30 mins at room temperature.
Slice the onions evenly. I used a grater to get nice even thin slices. Separate the strands with your hands for even browning.
Fry the Onions till golden brown on HIGH HEAT initially. Once slight brown, fry on LOW HEAT till golden brown. Do not brown them too much as they tend to get darker as they cool down. If too much browned they will taste bitter instead of sweet. Drain them on a Tissue and separate the strands to cool down.
Once cool down, make a course paste. Do not use water or make a fine paste. This coarse texture will give a good grainy texture to the gravy.
Soak few cashewnuts in hot water for sometime till they are soft.
Dry roast fresh or dessicated coconut on LOW heat for few mins till slight brown. I used Fresh grated coconut for better taste.
Dry roast green cardamom seeds, half of a Black Cardamom seeds, 1 inch cinnamon stick and small piece of Mace/Javithri on LOW heat.
Make a paste of the roasted coconut, cashews and the whole spices. Add some water to make a paste.
Keep 1 Tbsp of the oil in which the onions were fried, add 2 Tbsp Desi ghee. Do not throw away the remaining oil in which onions were fried, it is very aromatic and can be used for any curry or sabjis later. Add the whole spices and let them sizzle for some seconds.
Add the marinated chicken and Sear the chicken on High flame for 5-10mins.
Cover cook on LOW heat for 10-15mins. Once almost cooked, add the fried onion paste, coconut cashew paste and salt to taste.
Add some water, Cover cook for 10-14mins on Low heat. Add nutmeg powder.
Garnish with chopped coriander leaves and Ginger Juliennes.
Serve it hot with Butter Naan/Tandoori Roti/Paratha.