This is another one from those parts of the world. Those people are sure fond of their fermented fish. It is canned herring that supposedly has a strong pungent smell once you open the can, not a good recommendation to eat on the first date. Usually after opening the can people rush outside to eat it, in order not to cause other people to look at them with questioning gazes.
Surstromming is commonly served with snaps, light beers like pilsners or lagers, svagdricka (a type of light beer), water, or cold milk. What to drink with surstromming is disputed among connoisseurs (yes, there are people who call themselves that). Surstromming is usually served as the focus of a traditional festivity called a surstrommingsskiva. Whatever you think of Surstromming, it surely is an acquired taste.