I am a former chef and have eaten and cooked it a number of times like the one person said it has a sweetish taste like scallops, a bit mariney like a clam , buttery is another explative. When I worked in Japan, they really like them, both the white and black varietys, if you ever get a chance to see the episode of the Japanese Iron Chef series, they do one show devoted entirely to it. There to tenderize them the pressure cook them with daikon radish, it has an enzyme to help make it tender, lightly cooked like squid and octopus it can be a nice cold or hot item, mainly it is used in soups, braises and stews. They sell tinned ones in most large Asian grocerys, it is not cheap $10-20.00 a can, I have used it that way to in soups with another delicacy “shark fin”, both have very little distinct taste and absorb the flavours they are cooked with.