wash and hard boil the potatoes then peel the skin.keep in a large bowl and marinate with 1 tsp salt,lemon juice and turmeric powder ,keep aside for 1/2 an hour
heat the oil in wok add cumin and fenugreek seeds,as they pop saute ginger,garlic paste
roast onion ,add marinated potato and green chili stir for 2 minutes then add red chili,black pepper,dry mango powder,garam masala ,cook it for 5 minutes more and turn off the heat.
garnish with coriander and serve hot with pratha or tea .....