Peel, wash and cut potatoes in 1/2' * 1' pieces and place them in chilled water with ice for 30 mins.
Now on the gas put the Kadai and add Oil to it.
Heat the oil and add cumin seeds, green chilies and wait until these start to splatter.
Now add well drained chopped potatoes to the kadai.Mix propely with the cumin and chillies.
Cover and let it cook for 5-7 mins stirring it occasionally, just to prevent potatoes sticking to the bottom of the Kadai.
Now add salt ,Cumin powder ,black pepper and Mango powder and mix properly. Take care that potatoes do not get mashed. If required add a bit of more oil.
Cover and cook for another 15 mins, stirring occasionally.
When the potatoes are fully cooked, add fresh coriander and switch off the gas.Cover for another 5 mins before serving it hot with warm chapati's or puri's.