Line a steamer with several layers of cheesecloth and fill with the flour.
Steam for 45 minutes.
Make a well in the centre of the flour and add the hot water.
Place 6 filled thatu in the steamer and steam for 5 to 8 minutes.
*Can be found in some supermarkets and health food stores.
Note: A string hopper press is a tool used for extruding dough, similar to the way a pasta machine extrudes noodles. It is usually made of wood or metal and can be found in specialty Sri Lankan stores. Thatu mats - perforated discs made of plastic or woven bamboo - are the forms the string hoppers are steamed on. Thatu are also available at Sri Lankan stores.