Take 200 grams of singhare ka atta (water chestnut flour) in a bowl.
Add 1 teaspoon of rock salt (sendha namak), 1/2 teaspoon of red chilli powder, and 1/2 teaspoon of cumin seeds. Mix well.
Gradually add water and stir continuously to avoid lumps. Make a thick batter.
Heat 500 ml of oil in a kadai on medium flame.
Dip slices of 2 medium-sized potatoes in the batter and ensure they are well coated.
Carefully drop the coated potato slices in the hot oil.
Fry until they turn golden brown and crispy. Drain on absorbent paper.
Serve hot with green chutney or yogurt.