Fiddleheads? young fern sprouts?
DITCH THOSE! seriously, seriously ditch em. Don't eat that! jesus fucking wept, anywhere selling those from a store, needs environmental health sicking on them, fiddleheads are dangerous, and the adult fern parts highly poisonous not to mention carcinogens.
Main action of the toxic principles are carcinogen and thiaminase, destroys vitamin B1 in the body,depends on the species, but most contain the thiaminases. This can lead to a chemically induced form of beriberi, acute thiamine deficiency. Some but not all are carcinogenic. And in certain ones frequently consumed, there appears to be another toxin in action.
At the VERY least, boil them in a couple of changes of water before cooking them.
There was actually a case where some explorers in Oz ran down on their food on the return journey and used one of the fiddlehead ferns, in the genus Pteridium as a subsistence food. But neglected to cook the shit out of them enough. They starved to death, despite eating, because the thiaminase content destroyed their reserves of B1, and they couldn't absorb energy and sustenance from their food, it did not nourish them despite their eating enough food. There have been cases of foxes, incidentally, suffering fatal thiaminase toxicity due to
consuming thiaminases from carp intestines. This, is the main thermolabile toxic fraction in the common ferns used for fiddleheads. There are several others, the worst of which is probably an illudane glycoside called ptilaquoside, this appears to be so poisonous that there is a higher than usual incidence of stomach and mouth cancers in those who DON'T eat the fuckers, prseumably due to leaching into the water supply. Theres also shikimic acid in many, which appears somewhat toxic although nothing like as noxious as ptilaquoside. The latter damages DNA, is carcinogenic, and acutely toxic. In grazing sheep, partial blindness may result, and chronic consumption of unprepared or insufficiently prepared fiddleheads could potentially result in paralysis below the waist, due to the hydrogen cyanide content (will be leached out during cooking, but is volatile)
Overall thats a 'food' that might be eaten by people but really shouldn't, like false morels (Gyromitra) mushrooms (they are full of a compound that metabolizes to monomethylhydrazine, a heinously poisonous compound more widely known for its use by NASA for hypergolic rocket fuels. These are very popular especially in norway for some reason, but if not at LEAST twice-boiled and then boiled again preferably before cooking the way they are to be served. Quite a few cooks, who ate nothing of the dish, have ended up dead due to poisoning from the fumes, and they are so unpredictable that they sometimes have killed or poisoned several diners whilst several remain untouched due to variability to susceptibility to the toxic principle, gyromitrin)
And fugu, puffer fish sushi. Fiddleheads are up there in terms of nasty. And you, wolfy, of all people should avoid eating them, some of the toxins are haemolytic, targeting primarily red cells.
http://www.cdc.gov/mmwr/preview/mmwrhtml/00032588.htm