Marinade the chicken with curd, salt and turmeric and keep aside for at least an hour. Overnight is the best.
In a flat pan over low heat, dry roast all the masala ingredients apart from tamarind and garlic. Roast till the spices are fragrant and slightly browned. Set aside for cooling. This will take about 4-5 minutes on low flame but please be mindful to not burn the spices.
Once the spices are cool, grind to a smooth paste along with garlic and soaked tamarind paste. Keep aside.
In a kadhai, heat half of the ghee (1/4 cup) and add marinated chicken to it. Cook till chicken till half done. This should take about 5-6 minutes. Remove the chicken pieces and boil the curd mixture till it reduced half and thickened. Set aside.
In a separate kadhai, heat the other 1/4 cup of ghee. Add the ground masala, jaggery and curry leaf. On slow flame, roast the masala till the ghee separates. On low flame this will take 10-12 minutes, please be patient with this step. Add chicken and the curd gravy and cook it chicken is fully done and the masala thick.
Add more ghee if you want and serve hot with neer dosa, parota or just a glass of chilled beer