Boil the potatoes whole in salted water until a knife slides through easily, then drain and let them cool enough to handle.

Peel the boiled potatoes and mash them in a mixing bowl until smooth, with no large lumps remaining.

Heat one tablespoon of oil in a pan, add the mustard seeds and let them sputter, then add the chopped onion, green chili, and ginger, and sauté until the onion turns translucent.

Add the turmeric, garam masala, salt, and coriander leaves to the mashed potato along with the tempered onion mixture, stir until evenly combined, then set aside to cool to room temperature.

Divide the cooled potato mixture into eight equal portions and roll each into a smooth oval log shape.

Trim the crusts from the bread slices, dip each slice briefly in water, squeeze out the excess with your palms, then wrap it around a potato log and seal the edges by pressing firmly.

Heat the remaining oil in a kadai over medium heat until it shimmers and a small piece of bread dropped in sizzles immediately.

Shallow-fry the rolls in batches, turning occasionally, until every side is evenly golden brown and crisp.

Lift the fried rolls onto a paper-towel-lined plate and let them rest briefly so the excess oil is absorbed before serving.