Soak the saffron threads in hot milk for 15 minutes. Grind the fennel, cumin seeds, paprika, kashmiri garam masala & pistachios into a paste and add it to the yoghurt. Whip the yoghurt. Heat 1/4 cup of oil in a large pan. Add 1/2 of the onions and fry until browned. Remove & drain the excess oil on paper towels. Put the almonds and raisins in the same pan and fry until almonds are golden brown. Add cinnamon, cloves, bay leaves, nutmeg, cardamoms & peppercorns and fry for few minutes. Add garlc & the rest of the onions and fry until browned. Mix in the yoghurt mixture and stir for 2 minutes. Add the chicken, chicken broth & salt and mix well. Cover and cook for about 15 minutes until the gravy becomes thick and the chicken is half cooked. Add the mint leaves. Boil the rice with 5 cups of water and 1 tablespoon of oil over medium heat until half cooked. Drain in a colander. Transfer the chicken gravy in a large casserole. Spread the rice on top of it. Pour the saffron milk over the rice. Garnish with fried onions, almonds & raisins. Cover with aluminum foil and close the lid. Bake for 15 minutes at 400°F. then reduce the heat to 300°F and cook for 15 more minutes. Turn off the heat and let it be in the oven for 5 minutes. Serve hot with any raita, mint or coriander chutney.