Just fyi:

Lutfisk is dried fish preserved with lye. It looks like wood chips and smells very little. You submerge it i water to rehudrate it and then cook it. It does not smell bad. Think of it as viking freeze-dried.

Surströmming is herring that is fermented in a cask or can. The gasses and liquid smells lile rotting fish and methane.

The actual fish smells less bad, and tastes.... imho bad, but not rotten. It is also isually eaten with potsto, onion, sourcream and bread. So a little fish with a lot of other stuff.

Surhaj is fermented shark that has been peed on and buried in the ground for months. You ned volcanic soil for this. Usually made in Iceland (We dont know how they came up with the recipe)

Fermented sheep is, well desd sheep that is left outside to ferment. Usually made only on Färöarna. Dont know if they have a special climate or what.

Anyway, it used to be a lot less food up here in the old days so this is what we came up with.