Kokis are the lacy, wheel-shaped crisps that every Sri Lankan family fries in the days before Sinhala and Tamil New Year in April, piled onto the Avurudu table beside kavum, kiri bath and banana. A thin batter of rice flour, thick coconut milk, egg and a little turmeric is picked up on a hot brass kokis mould, dipped into the oil, and shaken free as it sets, so each one is light, salty-sweet and shatteringly crunchy. They're a cousin of the rosette cookie but savoury rather than sugary. The usual mistake is dipping the mould right under the batter, so the kokis sticks and won't release; dip it only three-quarters of the way up its sides. Chef's tip: heat the mould in the oil for a full minute before the first dip, and return it to the oil between every kokis; a cold mould won't pick up batter.