Oyster sauce describes a number of sauces made by cooking oysters. The most common in modern use is a
viscous dark brown
condiment made from sugar, salt and water thickened with
cornstarch, flavoured with a little oyster essence or
extract. Some versions may be darkened with
caramel, though high quality oyster sauce is naturally dark. It is commonly used in
Cantonese,
Thai,
Vietnamese and
Khmer cuisine.