The pot is named after a seasoning. Shottsuru is fish sauce: sandfish packed with salt and left for more than a year, until the fish has dissolved into a clear brown liquid that tastes of very little except depth. What is left in the bottle is mostly amino acids and peptides, which is a chemist's way of saying savouriness with the fish taken out of it.

The characters written for it mean salt liquid, or salt fish liquid, depending which version you use. It has been made in Akita since the early years of the Edo period. The smell is powerful, and people meeting it for the first time tend to pause once, with the lid still in their hand. Japan has only a few sauces of this kind — one on the Noto peninsula, one in Kagawa made from sand lance — and this is the northern one.

For the pot, the sauce is let down with stock and sandfish go in along with tofu and cabbage. So the fish is being simmered in a liquid made from its own kind. The same creature is in the bowl twice over, in two entirely different states.

Nothing was added to make it: salt and time did all of the work, in a province where the winters are long and the alternative was going without. A cupboard in a house here holds one bottle that took a year, and it is doing the job that a whole rack of jars does elsewhere.