Bring 8 quarts of water to a boil in a big saucepan.

Prepare a big dish of cold water.

Boil the geoduck for about 20 seconds, or until the skin of the trunk turns a shade darker.

Place the geoduck in icy water with tongs to halt the frying process.

Pull the skin away from the meat to remove it (a dry dishtowel can help to get a grip).

Gently pry apart the shell with a tiny boning knife and cut the flesh away from the shell edges.

Remove the sack from the body.

Slice the trunk thinly on the bias and serve with soy sauce, wasabi, or ponzu sauce.