Soak the rice. Wash the rice and soak for 2–4 hours, until softened enough to grind. Firmer boiled/parboiled rice may need longer or an overnight soak. Here, boiled rice means the uncooked parboiled grain, not leftover cooked rice.
Grind coarsely. Drain the rice and grind it with the coconut, salt and enough of the measured water to help the grinder work. Keep a fine, grainy texture rather than making a completely smooth paste. Mix in the remaining water gradually to form a thick, pourable batter; you may not need all of it at once.
Make the nesal. Heat the teaspoon of oil in a heavy-bottomed pan. Add the mustard seeds and let them splutter. Add the urad dal and cook until golden, then add the curry leaves and hing briefly.
Cook the dough in the tempering. Pour the rice-coconut batter into the same pan. Cook over low to medium heat, stirring and scraping the base continuously. The mixture should thicken, leave the sides and come together into a firm but pliable dough. If it becomes stiff while the rice is still undercooked, add a small splash of water and continue stirring. Switch off the heat when the dough holds together.
Shape while warm. Let the dough cool just enough to handle. Lightly grease your palms or moisten them with water. Take small lemon-sized portions, roll into balls and press a thumbprint into the centre of each.
Steam. Arrange on a greased steamer plate or idli stand. Place over already-steaming water, cover and steam over medium heat for 15–20 minutes. The pundi should be firm and cooked through, with no raw rice taste at the centre; allow longer if your rice or dumpling size needs it.
Serve hot. Serve with Kempu Chutney below and a cup of filter kaapi, or enjoy them on their own with the flavour of the nesal in every bite.