Wash, peel and cut potatoes into thin slices.
Soak them in salted water for some time.
Rub in between fingers and wash thoroughly 2-3 times, this will help releasing the water content.
Smoke mustard oil in a pan. Let it cool a bit.
Splutter cumin seeds.
Add in the sliced potatoes, mix well.
Cover and cook on a low flame till soften.
Uncover and cook on a high flame till crispy, do not stir a lot.
Next add salt, red chilli powder, coriander powder, amchur powder and turmeric powder.
Mix everything well.
Cook on a low flame without stirring much to make them crispier (optional).
Serve hot with roti or paratha.