Lizardfish or horse mackerel is grilled, the flesh flaked off the bones, and ground together with sesame in a mortar. Soy sauce and mirin go in, and the paste is packed into a jar. It is brown and looks, at a glance, like miso, though it falls off the spoon in crumbs rather than in a mass.

There is one canonical way to eat it. Put a spoonful on top of boiled udon, pour hot water over it, and the water becomes broth. No stock is made at any point. Nothing is simmered. The fish, the sesame and the soy were already broth before they went into the jar, and the hot water only reminds them of it.

Saiki is a port on the Bungo channel that lands fish all year round. The explanations offered for the paste are that it was a way of dealing with catches too large to sell, or that it saved the fishermen's wives the work of making stock every day. Both explanations are about not having time, which is usually the honest answer where preserved food is concerned.

That way of eating it, gomadashi udon, sits on the national list of a hundred rural dishes worth keeping. It is a condiment that turns into a meal if you add hot water. A jar kept on the shelf, which is also lunch.