First of all do chicken marination with ginger-garlic paste, garam masala, salt, curd, cumin powder, coriander powder, red chili powder, egg and cornflour. Add more flour if the mixture is too wet. keep for at least one hour.
Boil rice in water with salt, 2 green cardamoms, and 1 stick cinnamon, make sure to cook only 80% and should not be mushy.
cook chicken 65. Heat oil in a pan and saute red chillies and curry leaves. Add the marinated chicken pieces and fry till cooked and crispy
Heat oil in a pan and fry the onion slices. Keep aside
Now biryani masala, choose big pot to heat oil, add all the whole spices till they splutter. Add green chilli and ginger-garlic paste and saute for a minute. Add half of the fried onions and mix well, add tomatoes and rest of the spice powders. When tomatoes are cooked, add 2 tbsp curd and wait till it leaves water. Then add chicken 65 and simmer for 5-10 minutes
Now layer the biryani and take out half of the chicken mixture. Place half of the rice, sprinkle half of the mint leaves, coriander leaves and some fried onions. Also, splay 1 tbsp ghee over it. then add rest of the chicken mixture and rice, remaining mint and coriender leavs and fries onion.
Close the biriyani pot with a lid, seal the edges of the lid with dough or cloths or aluminium sheet, keep it on low flame for 10 minuts.
Then open the dum, just mix the rice and chicken pieces from the bottom of the pan using a long spoon.Enjoy the biriyani, serve hot with Raita, Pickle or salad.