Fermented you say?
Stinkheads
A traditional dish of the Yupik people of southwest Alaska, Stinkheads are fermented fish heads, most often King salmon. It was once customary to place the fish heads and guts in a barell, bury it in the ground and leave them to ferment, before consuming them. In modern times plastic bags and recipients started being used, but due to the high danger of Botulism, stinkheads are now buried stright in the dirt, in special burial pits. After a few weeks, when the salmon heads are all rotten, Stinkheads are ready to be eaten.