Peel 1 lb (500 g) potatoes using a vegetable peeler and cut them into ½ inch thick wedges. Soak the potatoes in water until ready to use.
Heat mustard oil in a pan. When the oil is hot, add asafoetida, cumin seeds and let them crackle for 5-6 seconds.
Add ginger and green chiliI and fry for 8-10 seconds.
Add potato wedges to the pan and fry for a minute.
Now add achari masala, turmeric powder, Kashmiri red chili powder, and salt to taste and mix well.
Cover the pan with a lid and cook on low heat until the potatoes are tender (10-12 minutes).
Once the potatoes are cooked well, add dry mango powder and chopped cilantro (coriander) and mix well.