A classic Chinese specialty made from the nest of an Asian bird similar to the swift. These birds attach their nests to cavern walls in Southeast Asia by using a gelatinous spit. Because of their hazardous location, the nests are dangerous to collect and therefore very expensive. White nests and black nests are the two types used. The more desirable of the two are the white nests, composed mainly of the weblike strands of saliva and containing few foreign particles. Black nests contain feathers, twigs and insects and are labor intensive to clean. Both types must be cleaned and soaked overnight before using. They're available in Chinese markets.