Boil the potatoes whole in salted water until a knife slides through easily, then drain, cool, peel, and dice them into small cubes.

Boil the soaked chickpeas in fresh water with a pinch of salt until they are fully tender and can be mashed easily between two fingers, then drain.

Simmer the tamarind pulp with the jaggery and a splash of water, stirring occasionally, until the jaggery fully dissolves and the chutney thickens to a syrupy consistency.

Blend the mint leaves, coriander leaves, and green chili with a splash of water into a smooth, bright green chutney.

Whisk the yogurt with a pinch of salt until it is smooth and lump-free, loosening it with a spoonful of water if it is very thick.

Toss the diced potato and boiled chickpeas separately with the roasted cumin powder, red chili powder, and a pinch of salt so they are seasoned and ready to layer.

Arrange the papdi in a single overlapping layer on a serving plate to form the base of the chaat.

Scatter the seasoned potato, chickpeas, and chopped onion evenly over the papdi, then spoon the whisked yogurt over the top in an even layer.

Drizzle the tamarind-date chutney and the mint-coriander chutney generously over the yogurt in crisscrossing lines.

Sprinkle the sev, chaat masala, and a little extra chopped coriander over the top, then serve the chaat immediately while the papdi is still crisp.