Surströmming for lunch
Surströmming cans should be opened in a ventilated are (outdoors) or at least fill a sink and open the can underwater. The cans have a high pressure and will easily spray inredibly foul smelling, sewer-grade putrid liquids.
The taste - it's just a sour and quite salty herring. Requires bread, potatoes or something else to go with it.
They make great gifts for the unwary!