Grind the batter: put the drained dal in a grinder with the green chillies and ginger and grind to a coarse, slightly grainy paste, adding water a spoonful at a time — you want a thick batter that falls off the spoon in heavy ribbons, not a pourable one. A batter ground too smooth or too wet steams into a dense slab, so keep both the texture and the water under tight control.

Season and rest: tip the batter into a bowl, whisk in the turmeric, lemon juice and salt, and beat it with the spoon for 2 to 3 minutes to lighten it a little. Cover and rest for 15 minutes while you set up the steamer.

Prepare the steamer: grease a deep plate or thali (about 8 inches) that fits inside your steamer, and get the water in the steamer boiling before the batter goes anywhere near it — the next step cannot wait around.

Activate and steam: stir the Eno or baking soda into the batter, fold it through quickly and evenly (the batter will froth and rise noticeably), and pour it straight into the greased plate, levelling the top gently. Steam on medium heat for 15 to 20 minutes, without lifting the lid in the first 12 minutes, until a skewer pushed into the centre comes out clean and the surface springs back when pressed.

Cool and cut: take the plate out and leave the khaman to settle for 10 minutes — cut too early and it crumbles and squashes. Run a knife around the edge, then cut into squares or diamonds in the plate itself.

Make the tempering: heat the oil in a small pan, add the mustard seeds and let them crackle, then add the sesame seeds, asafoetida, curry leaves and slit chillies and let them sizzle for a few seconds. Carefully pour in the water (it will splutter), stir in the sugar, lemon juice and salt, and boil for a minute until the sugar dissolves.

Finish and serve: spoon the hot tempering evenly over the cut khaman, letting it soak down into the cuts — this is what keeps every piece moist right through. Scatter over the coriander and coconut and serve warm, on its own or with green chutney.