Cut the chicken into medium sized pieces. Wash and drain well.
In a grinder, grind together ginger, garlic, green chillies and yogurt into a smooth paste. Add in to the chicken.
Add ingredients from pepper powder to salt and rub well into the chicken.
Allow the mixture to marinate for at least an hour or as much as possible.
In a cooking pot (preferably the one for dum), add 2 tbsp ghee. Add the marinated chicken, completely with all the marinade - you may use some water to clean up all the marinade - and allow the chicken to cook on low flame, stirring occasionally, till almost done.
Meanwhile, wash the basmati rice. Cook in lots of water with some salt and the whole spices till done. Drain and set aside.
Once the chicken is almost done, layer the cooked rice on top of it. Sprinkle some fried onions and chopped mint leaves and the remaining ghee on top. Cover the lid tightly and cook on dum for around 15-20 minutes.
Switch off and allow it to rest for another 10 minutes.
To serve, fluff the rice to mix with the masala. Serve hot with raita, pickle and a thick gravy if needed.