Marinate chicken pieces with ginger-garlic, yogurt, turmeric, salt and 1 tsp mustard oil. Set aside for 1 hour.
Cut the onion and tomato into two halves. Transfer to a pressure cooker with a little water and boil for 3 whistles. Allow to cool down. Drain away the excess water and mash the onion and tomato. Do not throw this water.
Cut the potato into 4 pieces, fry for 3-4 minutes and keep aside.
Heat a pan. Add cumin seeds, coriander seeds, cardamon, cinnamon, mace and star anise. Dry roast for about 2 mins. Grind into a fine powder in a mixer grinder.
Heat the oil in a pressure cooker. Add cumin, fennel seeds, bay leaves and red chillis followed by the mashed onion and tomato. Cook for 3 mins.
Add the ginger garlic paste and salt. Fry the paste for about 5 mins.
Add the marinated chicken pieces along with the roasted spices and kashmiri lal mirch powder and cook for 10-15 mins with the lid open. Keep stirring in between.
Add potato pieces, 2 cups hot/warm water, salt if required and allow for 1 whistle.
Keep aside till steam is released. The chicken should be just tender and not overdone. If it is still not done, cook for another whistle.
Serve with white rice . ( Add some ghee over it if you are suffering from cold )