Like Japanese harusame (made with potato starch) and shiratake (yam starch), and Chinese cellophane noodles (bean starch), Tang myun are transparent when cooked and are therefore often called glass noodles. They are the base ingredient in many Korean noodle dishes, notably japchae, which is arguably Korea's national dish. Cooked for about 6 minutes and rinsed thoroughly, these noodles are slippery and have a very nice chewy texture. They take on the flavour and colour of their sauce – which in the case of japchae is a beautiful, mahogany-coloured concoction of 3 parts soy sauce, 3 parts gochujang (Korean hot pepper paste) and 1 part toasted sesame oil.