Duck is sliced thin and dusted with wheat flour before it goes into the pot. The flour does two jobs at once: it seals the meat, and as it comes away it thickens the broth. One gesture, two results, which is the kind of economy that suggests a professional kitchen rather than a farmhouse.

Sudare-fu goes in with it, a ridged wheat gluten cake made in Kanazawa that soaks up liquid the way bread does. Then shiitake, and a green, usually water dropwort or spinach. At the end a small mound of wasabi is set on top, and that single detail is what separates the dish from every other simmered bowl in Japan.

Explanations of the name multiply. Some say it comes from the sound of the simmering. Some attribute it to a man's name, an official who is supposed to have brought the method back from the continent. A cookbook written by a chef in the service of the Maeda lords in the early eighteenth century describes something very close to it.

Thickened broth, and cold wasabi on top of it. Whoever arrived at that combination thought about it for a while. It was served to the emperor on his postwar tour of the country in 1947, which tells you where the dish sits locally: not everyday food, but not museum food either.