In another pressure Cooker, heat oil, add all the wholes spices. Saute for couple of seconds.
Then add the onion julienne, green chilies, followed by the ginger garlic paste, saute well. Add chopped tomatoes and saute well. Once the tomatoes get soft, add the ground masala to it and cook well till the oil comes out.
Now add the cooked chicken and saute well to make sure the chicken coated with masala. Add coconut milk, water and adjust spice.
Add the drained rice and bring to boil. Cover with lid and cook for 1 whistle. Simmer completely and cook for 10 mins.
Wait for the pressure to fall, fluff the rice well.
Grease a nonstick pan with ghee, spread the cooked biryani nicely and cover with a thick lid and dum cook for another 15 mins.
Remove and finally add the lemon juice.
Serve with Onion Raitha or chicken gravy.