Wash rice till you get clear water, soak for minimum 2 hrs before cooking.
Wash chicken pieces nicely and then marinate them with curd, 1 tsp lemon juice, red chili powder , turmeric, coriander powder and some salt. Keep the chicken marinade for about 45 mins before cooking.
Heat oil in a big wok or a handi and add all the whole spices mentioned above and allow them to crackle.
Now add chopped onions and fry them till soft
Now add the ginger garlic paste and fry the mix till it becomes golden in color.
Add the green chilies and few leaves of mint and some coriander in it and fry well.
Once the oil starts leaving the sides, pour in the marinaded chicken along with the left over marinade mix and mix nicely.
Keep the flame high. You may see the curd leaving water from sides. Fry the mix till the water evaporates completely. Keep stirring in between.
When the chicken mix starts getting thick, add grounded coconut, khuskhus paste (soaked khus khus grounded into a paste) and fresh cream into it. Mix properly till everything incorporates well.
Adjust salt and check.
Give a stir and close the lid. Simmer the gas flame and let the chicken cook till it gets tender.
Once the chicken is fully cooked, you will see oil oozing out from the sides. Turn off the gas and keep the yakhni aside.
Meanwhile proceed to cook rice...
In a large vessel heat water double the quantity of rice.
Add 1 tsp lemon juice in it and some oil (1tbsp)
As soon as the water is hot, add the soaked rice and allow it to cook in high flame.
Add salt to the rice and let it cook till its 80% done.
Drain the water and pass the rice through a colander. Spread it on a large tray, so that it doesn't get sticky.
Assembling for Dum ....
Heat a broad base flat iron tawa on gas and place a large handi on it.
Add some curd in the base of the handi to prevent the yakhni from sticking.
Layer the chicken mix (yakhni) equally on the base and add a spoon full of ghee here and there.
Now add the rice on top and garnish it with ghee, saffron soaked milk, mint, coriander, lemon juice, kewra water and some nuts if you wish.
Seal the handi with aluminium foil and cover it with the lid with something heavy placed over it.
Allow the biryani to be on dum for around 30 mins.
Remove the foil from one side and mix the biryani well (do this carefully as the rice may break here)
Serve hot with raita and salad.