These tiny, milk-white fish, also known as whitebait, are pulled in by the millions in fine nets from the waters of the South China Sea. Cousins of the anchovy, the slender fish, ranging from about 1½ to 3 inches long, were historically used as bait by Chinese fishermen. Hong Kong decided to cook them. These days, they are served mounded on plates as a welcoming food in restaurants, to be nibbled on as you peruse the menu, or as small, elegant dinner introductions to whet the appetite, no more than two or three to a plate. It is a new custom that has traveled beyond Hong Kong as well. Look for these fish frozen in 1-pound boxes in Chinatown markets. They are imported from China and usually labeled “silver fish” and “wild caught.” Even whitebait found loose in fish markets are simply these same imported fish that have been thawed. They are simple to cook, but demand attention to detail to turn out well.