The best part of the salmon, they will tell you here, is not the fillet. It is the head, the spine, the base of the fins, the parts a city kitchen throws away without thinking. Ishikari nabe is built on that conviction. The bones do not go into the pot to make a stock and then come out again; they go in to be eaten, and you are expected to work at them with your fingers.

The broth is miso. Onion, cabbage, potato and tofu go soft in it, and the fat rises slowly and sits on the surface in gold coins. Most households finish the pot with a shake of sansho pepper, which cuts the richness and wakes the whole thing up. Some stir in sake lees, some drop in a knob of butter. There is no settled recipe, only the version your family makes, and people are quietly certain that theirs is the right one.

The dish began at the mouth of the Ishikari River, among people who caught the fish and ate it on the beach on days when the catch was good. A restaurant that opened there in 1880 turned that into something you could order. The onion and cabbage, and the sansho, appear to have been its ideas rather than the fishermen's. This is food you suck off a bone, in a room where the windows have fogged over and nobody is dressed for company.

And yet the old claim about warming you from the core turns out to be simply true, which is not something you can say of most winter dishes. The last of it, at the bottom of the pot, is the best.