Firstly, clean, rinse and soak the rice in sufficient water for 30 minutes.
Prepare the potli masala; take a piece of cloth and place all the spices mentioned for the potli masala on the cloth. Bring the edges together and tie a knot on the cloth to keep the spices safe under the knot.
Add 2 cups of water to a pressure cooker. Add cinnamon, cardamom, cloves, black cardamom, bay leaves, roughly chopped onion, garlic cloves, roughly chopped ginger and salt to taste. Close the lid and let the whistle come on a high flame.
After 1 whistle, turn off the flame and let the pressure settle down. Open the lid and add chicken pieces and 1 tsp of lemon juice. Mix it well and close the lid.
Let the whistle come on the high flame. After 1 whistle on a high flame, turn it to low and cook it for 2 minutes. After 2 minutes, turn off the flame and let the pressure settle down.
Open the lid, discard the potli and strain the chicken in a strainer. Discard all the spices and keep the chicken stock for the biryani.
Heat oil in a kadhai on a medium heat. Add thinly sliced onions and stir them continuously. Fry the onions until light golden brown. Strain the onions and transfer them to a plate.
Add cumin seeds, bay leaf, cardamoms, cloves, cinnamon, black peppercorns, and star anise in the same oil. Let them crackle.
Add fried onions (save some fried onion slices for the garnish), ginger garlic paste and chilli paste. Stir it well and cook it until the raw smell of ginger garlic fades away.
Add cooked chicken pieces, curd (beaten well), coriander powder, fennel powder, slit green chillies and salt to taste. Cook them on a medium-high flame until the raw smell of spices and curd disappears and oil starts to release from the sides.
Add 4 cups of water + chicken stock. Let it come to a rolling boil.
Add soaked rice, lemon slices and nutmeg powder. Check the seasoning and mix it well.
Cook the rice on high flame and bring it to a rolling boil. Cover the lid, cook it on high flame for 2-3 minutes, then reduce the flame to low. Cover and cook for 7-8 minutes or until the rice is cooked and all the water is absorbed.
Add 1 tablespoon of water, 2-3 drops of orange food colour and kewra essence in a bowl. Mix it well.
Add this mixture on the biryani and cover the lid. Let it simmer for 1 minute, then turn off the flame.
Leave the biryani to absorb all the flavours. Open the lid after 15 minutes.
Gently mix the biryani and serve it on a serving plate.
Garnish it with fried onions (barista) and mint sprigs. Serve it with raita or spicy chutney.
Chicken Potli biryani is ready to serve.