Cockles are in season during the summer.They live in shallow waters and feed on plankton. Torigai directly translates to “bird clam” and this is because the foot that sticks out of its shell resembles a bird’s beak. Cockles use these feet to jump and evade predators such as the starfish.
Cockles must be fresh and must never be frozen, or their quality drops significantly. The body of the cockle (which is not consumed) contains a lot of sand and debris, so the foot is removed,butterflied and lightly poached at the fish markets and sold in containers, but serious chefs buy them un-shucked and prepare it themselves.
Apart from used in Sushi, Cockles are cooked as snack, boiled, then seasoned with malt vinegar and white pepper,sold as pickled in jars, and more recently, have been sold in sealed packets (with vinegar) containing a plastic two-pronged fork. They are used in laksa, char kway teow and steamboat. They are called kerang in Malay and see hum in Cantonese.