Place the four platters/thalis upside down on a clean surface. Have your spatula to hand, ready to start spreading the dough as soon as it is ready.
In a large mixing bowl, whip the yoghurt with the water, add the salt and slowly add the chickpea flour, stirring until it well blended. Heat the mixture on high heat in a saucepan, stirring continuously until it starts thickening.
Cook the mix until it becomes very thick, almost like a bread dough. Remove the pan from the heat.
Take a large dollop of the dough (roughly the size of a cricket ball) and start spreading this on one of the inverted trays. It is extremely important to do this quickly because all the spreading on all four trays has to happen before the dough cools down and sets. Use long, even strokes, applying some pressure to get a thin (2-3mm thick) layer all over the tray.
Repeat this process for all four trays and leave them to cool and set.
In a small pan, heat the oil. When hot, add the mustard seeds and let these crackle.
Add the chopped chillies, stir for 1-2 seconds and turn the heat off. Now add the turmeric and SSP asafoetida and stir. Let this mixture (the “tadka”) cool.
Now turn back to the trays. Using a knife, make long parallel cuts about 5 cm apart from each other, into the set chickpea-yoghurt dough on the back of the tray. Gently lift the edge of one of the strips and start rolling – it should come away easily from the surface of the tray. Repeat this process for all four trays.
Arrange the rolls on a dish. Squeeze the lime juice over them. Sprinkle with chopped coriander. Drizzle with the tadka and serve.