Also called dow gok, yard-long beans, and snake beans, Chinese long beans can grow up to a yard in length. They are tender and similar to string beans, but the two vegetables are actually not closely related. Rather, Chinese long beans are in the same family as the black-eyed pea, and if left to mature fully, long beans will develop full peas in the pod.
Chinese long beans are available at Asian markets, farmers' markets, and some supermarkets year-round, with a peak season in the fall. Look for beans that are smaller (which means younger and more tender) and flexible. The peas should not have matured, and the beans should have no dark spots.
Trim off any dry ends, then break or cut Chinese long beans in half before cooking. They should not be used interchangeably with green beans. Their mild flavor works well with strong, spicy seasonings; try them in stir-fries, either with other vegetables or on their own. They are also excellent deep-fried. Be careful not to overcook them to avoid mushiness.
Refrigerate long beans in a plastic bag for up to five days.