The small gizzard shad is filleted, cured in salt and then in vinegar. Millet is steamed, cooled, mixed with ginger and chilli, and layered alternately with the fish in a container. The millet has been dyed yellow with gardenia, so when the lid comes off there are bands of yellow and silver, which is more or less the point.

The fish changes its name as it grows: shinko, then kohada, then nakazumi, then konoshiro. Fish that are renamed on the way up are treated as auspicious, and so it earns a place in the New Year boxes. The yellow millet is there for a good harvest. Two separate pieces of good fortune, stacked in one small dish, which is roughly how New Year food works.

Among the fish of Tokyo Bay, kohada is the one that takes the most preparation, and sushi chefs use it to demonstrate what they can do. The curing has to be judged rather than timed, and a stronger hand with the vinegar buys keeping time as well as flavour, which mattered when this was made in late December to be eaten a week later.

But this is not the sushi counter's version. This is the one made at home in December and eaten cold on the first of January, out of a lacquer box, which turns out to be a different fish entirely.