heat the butter in a pan.
now roast the gram flour for 2 minutes
make a fine paste with onion,chillies, ginger and garlic
marinate the chicken with all the ingredients except oil
marinate the chicken for 1 hour
now heat up oil (not more than 120 degree)and ghee in a flat heavy bottomed Kadhai.
pour the marination and chicken pieces in the kadhai
cook the chicken pieces in low flame for 2 hours
Serve chicken Chaap with biryani.