First make the quick chutney.
Put the tamarind paste, dates and 300ml water in a saucepan, bring to a boil, then turn down to a simmer and cook until the dates are tender.
Take off the heat, leave to cool, then puree.
Stir in the sugar, cinnamon, chilli, cumin, chaat masala and kala namak, if using.
The chutney should have a thick, pouring consistency a bit like ketchup, so add more water if required.
Cover and refrigerate until needed.
Chop the potatoes into bite-sized pieces, then boil in salted water until tender.
Drain, leave to cool completely, then arrange the potatoes on a platter.
Scatter over the drained chickpeas, season with sea salt and pepper, and mix.
Drizzle over the date and tamarind chutney, dollop on the yoghurt here and there and top with the sev, onion rings, coriander and pomegranate seeds.
Serve at once.
