Idli is breakfast across Tamil Nadu, from Chennai's Mylapore tiffin rooms to village kitchens, and a fluffy, plain idli is one of the first finger foods many South Indian babies hold. Since family batter is salted, parents make a separate salt-free batch for babies under one, or steam a few from it before the salt goes in. The cakes are pillowy, faintly sour and melt under the gums, torn into pieces or mashed with ghee or thin dal. They contain no gluten, egg, nuts, soya or sesame; they contain milk only if served with ghee. Chef's tip: grind the urad dal with ice-cold water until it is light and foamy; air in the batter, not salt, is what makes idli soft.