Còi biên mai (pen-shell adductor muscle)

Còi biên mai is the thick adductor muscle of a large pen shell. It has a naturally firm, springy texture and clean sweetness. Whether grilled with chilli salt or cooked with satay, the key is to stop at just-done so the meat stays juicy rather than turning dry and tough.

Choosing and ordering food

Grilled còi biên mai is a good dish to share. Because each adductor muscle is thick, it needs only enough heat to cook through while keeping its snap and moisture. If you are in a small group, ask about the portion size before ordering because the pieces can vary considerably between catches.

What to know when ordering

The word còi refers to the muscle that opens and closes the shell; it is not the name of a separate seafood species. The texture is supposed to be firm and springy, but too much heat quickly makes it chewy and dry, so the cook’s timing matters.

Before eating or buying

Ask whether the portion contains only the separated adductor muscles or comes with the whole pen shell.
Ask for less chilli if you want the natural sweetness of the meat to come through.
If you have a mollusc allergy, tell the restaurant before ordering.
Eat it soon after it leaves the grill, while the meat is still juicy and springy.