Whisk the thick curd until completely smooth in a large bowl.
Add boiled cubed potatoes, sliced onions, chopped green chilies, chopped coriander leaves, salt, sugar, amchur powder, and Kashmiri chili powder. Mix well and set aside.
Heat mustard oil until smoking hot in a small pan.
Add extra Kashmiri chili powder, turmeric powder, and kasuri methi into the hot oil, then take it off the flame.
Pour the tempering over the potato mixture, mix well, and serve immediately with hot steamed rice.
