Wash and soak each of the first 3 ingredients overnight, separately. Next morning put the dry yeast in a bowl with sugar and 3 tablespoons warm water. When it is bubbly and rises, add it to the rice (both kinds) and the lentils which have been ground fine in the blender/grinder with the coconut milk. Add salt to taste and keep aside for 5 hours till it doubles in quantity. Get the steaming vessel ready on medium flame with the required amount of water in it. Put a tablespoonful of the batter into each of the moulds and steam on medium heat till the sannas are fluffy and done right through. Makes about 36 sannas.