Periwinkles - the animals, not the flowers - are molluscs,
more specifically sea snails. They are commonly
eaten as "winkles" in England and Ireland.
I found them, de-shelled, in the frozen food section
of the Asian grocer and had to try them out for myself.
One thing about these - you cannot cook them for
too long or they turn tough. That happened the first
time I sauteed
them in garlic butter. However, when I boiled them
lightly - bring water to a rolling boil, then dump the
thawed periwinkles in and boil them for three minutes
- and served them with the same garlic butter (Melt
a few tablespoons of butter over medium low heat, then
add two cloves of finely minced garlic.
When the garlic softens, mush it up with the back of
a spoon. Let simmer for a few more minutes, then serve.)
they came out fine. Really, they would have been fine
when I sauteed them if I hadn't left them on the heat
as long as I did.