2 Tsp black mustard seeds
1 Red onion, finely chopped
6 Cloves garlic, crushed
2 Tbsp finely chopped ginger
1 Tsp ground turmeric
2 Tsp cumin seeds
2 Tsp amchur (mango powder)
1 Large green chilli, sliced
Small handful curry leaves
500g chat potatoes, cut into quarters
2 x 400g can chickpeas, drained and rinsed
680ml (2¾ cups) water, approximately
350g (1¼ cups) tamarind and date chutney
Medium sev (fried chickpea noodles; see Note), to taste
Heat the oil in a large saucepan over medium-high. Add the mustard seeds and cook for 2-3 minutes or until the seeds pop. Add about ¾ of the onion, the garlic, ginger, turmeric, cumin seeds and amchur and cook, stirring, for 4 minutes or until the mixture no longer smells raw. Add the chilli, curry leaves and potato and cook, stirring often, for 5 minutes or until the potatoes start to soften. Add the chickpeas and 500 ml (2 cups) of the water. Season well with sea salt and freshly ground black pepper and bring to the boil. Cover the pan and cook for 5 minutes then remove the lid and cook for another 12 minutes or until the potatoes are cooked and the liquid has evaporated.
Meanwhile, gradually combine enough of the remaining water with the chutney in a bowl to form a thick, spoonable mixture; you might need more, or less, water. Divide the chickpea mixture among bowls, spoon some of the tamarind chutney mixture over and scatter with the remaining onion and sev noodles to taste. Stir the mint into the yoghurt and serve on the side along with remaining tamarind chutney.