01 -
Preheat the oven to 220°C fan. Put the potatoes and 2 teaspoons of salt into a medium saucepan and top with enough cold water to cover by about 4cm. Place on a medium-high heat, bring to the boil, then simmer for 6 minutes, or until they're almost cooked through but still retain a bite.
02 -
Drain potatoes through a sieve and pat dry, then transfer to a large parchment-lined baking tray. Toss with the oil, chaat masala, turmeric, ⅓ teaspoon of salt and a good grind of pepper. Roast, stirring once or twice, for 35 minutes, or until deeply golden.
03 -
Put all the chutney ingredients into the small bowl of a food processor and blitz until smooth. Set aside until needed.
04 -
Whisk together all the dressing ingredients in a small bowl and set aside.
05 -
Spread the yoghurt out on a large round serving platter. Top with the coriander chutney, swirling it through without completely incorporating. Drizzle with half the tamarind dressing, and top with the potatoes, onion and chilli. Drizzle over the remaining tamarind, then sprinkle over the seeds and serve.