Fermented shark!

Fresh Greenland shark is poisonous when fresh, because of high levels of urea and trimethylamine oxide. So you have to let the shark fully rot to get rid of the toxins. You dig a hole in the sand and bury the shark for a couple months and then you dry it. Hákarl has a lot of ammonia and thus smells like floor cleaner. I wish I had known beforehand that I was supposed to wash it down with the local grain alcohol.

https://youtu.be/-FenXUtXu0E