Marinate the chicken and set aside.
Heat a tsp of ghee and add all the "for roasting" ingredients. Roast for a few minutes till a nice smell comes.
Add 1/2 cup of water and boil till the chillies become soft. Allow to cool.
Peel the tamarind well into the soaked water and discard. Add the water into the roasted mixture and grind into a smooth paste.
In a wide saucepan, add the chicken along with the marinade and cook till it is almost done.
Meanwhile, in another saucepan, heat the remaining ghee. Add the paste and cook till the ghee floats up. Keep sauteing to avoid sticking at the bottom.
Add the chicken along with its stock into this post and cook on low flame till the chicken is completely done and the sauce thickens. Adjust the salt. In case sour, add sugar to adjust. Garnish with coriander leaves and serve hot.