Heat a kadai and dry roast coriander seeds, cumin seeds, black peppercorns, fennel seeds and red chillies. Transfer this mixture into a mixer jar and coarsely grind it.
Heat oil in a non stick pan and add asafoetida, kalonji, ginger and garlic and sauté.Add the potatoes and sauté.
Add red chilli powder, dried mango powder and salt and mix well.Add the ground masala mixture and mix well.
Transfer in a serving plate and serve hot.