Thalassery Chicken Biryani

This is the first time I'm making a Thalassery Biryani, from Ummi Abdullah's book Malabar Muslim Cookery. I have given her exact recipe from the book, but I didn't add cashews and raisins as I don't like much dry fruit in biryani personally.
We had it with raw papaya thoran, pappadam and fried mackeral fish। A thoran is not necessarily served along with a biryani meal, it would usually be fried fish, pappadam , pickle and raita. But since I had some raw papayas at home, I decided to make the thoran,which quickly made friends with the biryani at the table.
Chicken Biryani- Ingredients
1 Kg Chicken
1 Kg Pulao Rice ( I use a small-grained biryani rice from Calicut called Kaima, but Jeera rice works well too )
500 gm onions
250 gm ghee or oil
100 gm green chillies
50 gm ginger
50 gm garlic
1 tsp poppy seeds
pinch of d=saffron or yellow food colouring
2 tsp garam masala powder ( I used my own)
1 cup curd
1 bunch coriander leaves
small bunch mint leaves
20 gm sliced cashewnuts
20 gm raisins
Juice of 1 lime
2 tsp rose water

Ummi Abdullah's Garam Masala ( Dry Grind the following spices to a powder )
2 gm cinnamon
1 gm green cardamom
1 gm cloves
1/4 Nutmeg
1/2 tsp anise seed
1/2 tsp cumin seed
1/2 tsp cake seed
2 gm mace

1. Slice the onions fine.
2. Grind the green chillies, ginger, garlic, and poppy seeds.
3. Chop the coriander and mint leaves
4. Heat a heavy bottomed vessel and add half the ghee. Add half the sliced onions and fry till transparent.
5. Add the ginger-garlic,chillies and poppy seed paste and fry for 2-3 minutes
6.Add the chicken and fry a few minutes more.
7. Add the beaten curd, salt and 1/4 cup warm water. Cover and cook on a slow fire.
8. When the chicken is half cooked,add the lime juice, coriander leaves and mint leaves. Cook till the chicken is tender and the water is absorbed.

9. Wash the rice and drain it in a colander.
10. Heat the rest of the ghee in a vessel. Add the pother half of the onion and fry till golden brown, add the cashews and raisins and fry with the onions. Remove and keep aside.
11. Add the drained rice and fry for 5 minutes. Add double the quantity of hot water and cook the rice till soft and the water absorbed.
12.Take the vessel with the chicken and sprinkle some of the garam masala powder on to the chicken masala.
13. Put one layer of cooked rice on top of the chicken masala. Sprinkle some garam masala powder, some fried onion, cashew nuts and raisins and some saffron/ food colouring soaked in rose water.
14.Finish with two more layers of rice the same way.
15.Cover with a heavy lid.
16.Place some live coals on top for 15 minutes or put the dish in a pre-heated oven for 15 minutes.