Dissolve the yeast and sugar in the water and set aside for 5 minutes. Sieve the flour and salt into a bowl, add the coconut milk, yeast and sugar and mix to form a smooth batter. Cover and leave overnight. Grease a hopper pan, heat it over a moderate heat and pour 75 ml of batter into the pan. Tilt the pan so batter forms a round shape, cover with the lid and cook until done. Ease the hopper from the pan with a blunt knife. From "A taste of Sri Lanka" by Indra Jayasekera, Isbn #962 224 010 0