Khandvi | Thin Rolled Chickpea-Flour Snacks

Lightly grease a marble counter or the backs of two large trays with a few drops of oil. The surface should have only an almost invisible film. The mixture must be spread as soon as it finishes cooking; if you prepare the surface afterward, it will set in the pot. Have a wide, flexible spatula ready.

Sift the chickpea flour into a bowl, then gradually whisk in the buttermilk and water. The mixture should be completely smooth; any lumps will leave holes in the finished layer. Whisk in the grated ginger, finely chopped green chili, turmeric, and salt, then whisk one more time and pass the mixture through a fine-mesh strainer.

Transfer the mixture to a heavy-bottomed pot and cook over medium heat, stirring constantly with a wooden spoon. It will foam at first, then thicken and become glossy enough to coat the spoon, in about 10 minutes. To test it, spread 1 spoonful of the mixture thinly on the greased plate and wait half a minute before lifting it with a finger: if the layer lifts intact, it is ready; if it tears, cook for 2 more minutes.

Remove the pot from the heat. Immediately pour the mixture onto the greased surface and spread it as thinly as possible with the spatula, until light can pass through. Let it cool for 3 to 4 minutes, then cut long strips 3 cm wide with a knife and roll each strip tightly, starting at one end. Arrange the rolls side by side on a serving plate.

Heat the oil in a small skillet, add the mustard seeds, and partially cover the pan until they stop popping. Add the sesame seeds and heat for 10 more seconds, then turn off the heat. Spoon the hot tadka (spiced oil tempering) over the rolls, sprinkle with chopped fresh cilantro, and serve at room temperature.