There are no noodles in it. What lies in the bowl is bean-thread vermicelli, sunk in a pale broth, with a stir-fry heaped on top: prawn, squid, pork, Chinese cabbage, bamboo shoot, wood ear.

Beside that sits a single egg, boiled and then deep-fried, so that the white blisters and wrinkles and takes on a striped brown surface. The Chinese name for it translates as tiger-skin egg. In the original dish this was a duck egg; duck eggs were not to be had here, so a hen's egg went in instead and never left.

The dish came from Fuzhou, in Fujian, and is said to have been brought to Kumamoto by Chinese residents who settled here in the Meiji period. It did not arrive as an exotic import to be admired from a distance. It arrived as somebody's ordinary lunch, cooked by people who had moved here and gone on eating what they had always eaten.

Now it is a fixture on the menu of every Chinese restaurant in the city, and it turns up on the school lunch rota here and in several towns north and south of it, which is a different order of belonging altogether. A foreign dish becomes local at the point where children read its name on a printed sheet at the start of the month and think nothing of it at all.