Take boiled potatoes. Peel off skin and roughly crumble it into medium and small chunks.
Add flour, black pepper & rock salt. Add 1/4 cup water slowly and gradually to make a medium thick consistent batter. The batter should be of thicker consistency.
Heat oil in a pan or kadai.
Once oil is hot, take 1/2 - 1 tsp batter mixture and drop it into hot oil. When its golden brown flip to other side.
Once done both sides remove from heat and transfer to a clean plate.