Take all the ingredients in Masala A and dry roast lightly and grind to a fine powder.
Wash the Chicken and put it in a colander for water to drain completely. Pat Dry. Marinate the Chicken with the ground Masala A and Yogurt.
Add Ginger Garlic paste, Red chili powder and Turmeric Powder to the chicken. Mix everything well and refrigerate for 5-6 hours.
Add a tbsp of ghee to a pan. Add ingredients listed under Masala B.
Add 12-14 cups of water. Add little salt and let the water come to a boil. Once the water starts boiling, add Rice and cook for around 7-8 minutes till half done.
Drain the water and transfer the Rice to a wide flat dish.
Heat little Oil in the pan. Add the sliced Onions.
Fry till they are golden brown in color. Take them out and set aside.
Boil the Potatoes for 10 minutes, till they are 75% done. Peel and slice them. Add them to the same pan as the onions and lightly fry them and keep them aside.
Fry the cashew nuts to a rich gold and light brown in color. Remove and set aside.
Add little oil to the pan. Add the chopped onions to the same oil. when the onions turn pink, add all the ingredients in Masala C and fry for a minute.
Add the remaining ginger garlic paste and cook well. Remove it from the pan.
Let it cool down and put it in a blender.
Grind to a smooth paste.
Heat Oil in the pan. Add the marinated chicken and cook for around 10 minutes.
Add the ground masala C and cook further for 5-7 minutes.
Stir frequently. Cover and cook for around 7-8 minutes, till chicken is cooked and it has only around 1 cup of gravy left.
Assemble and serve: Take a heavy bottomed pan and smear it with oil. Arrange the potato pieces in first layer.
Sprinkle some Rice and fried onions over it.
Place half of the chicken. Then add Rice and again Chicken.
Finally Add the final layer of Rice. Spread the Rice all around to cover the Chicken. Make 3-4 holes with a wooden spoon and pour the saffron milk into the holes. Cover the holes again with Rice and and smoothen the surface. Pour 2 tbsp of Ghee over the Rice and spread some fried onions as well. Cover the Biryani vessel with a cloth followed by a tight fitting lid. Leave it for Dumm.
If placing in the oven, it should be pre heated at 350F. Place it in the oven for 30-40 minutes. If using the stove, place the Biryani vessel on a Taa’wa and cook on high flame for 5 minutes and then on medium to low for 25 minutes.
Take out in large chunks from the sides and serve hot.