Add turmeric powder, red chili powder, roasted garam masala, salt and mustard oil to the chicken and mix it well.
Keep marinated chicken aside for half an hour.
Add mustard oil to the heated pan.
Add the potatoes to hot oil. Add some salt and turmeric powder. Fry the potatoes until light brown.
Take the fried potatoes out of the pan.
Add the whole spices such as bay leaves, cinnamon sticks, green cardamoms, cloves, pepper and cumin seeds to the oil. Saute until they emit flavour.
Add sliced onions and fry them light brown.
Add chopped tomatoes and some salt. Sauté till tomatoes become tender.
Add ginger-garlic-red chili paste. Mix well.
Add chicken pieces. Given them a good stir. Here comes the importance of arm-twisting or kashano (what we Bongs fondly call it).
Add potatoes. Sprinkle some salt. Add a little bit of water. Resume your kashano work.
After water gets dried, add 1 and ½ cup of water and cook with the lid on.
Remove the lid. Water has now come to a boil. Add coriander and cumin powder.
Towards the end, add the roasted garam masala powder and mix well.
Chicken potato curry is ready now. Serve it with steamed rice, pulao, roti and paratha etc.