Oyster sauce is a cooking sauce made from oysters and soya beans. It has a thick texture, shiny appearance and a slight fish taste. It is used to flavour fried vegetables in stir-fry dishes, it gives a soft, slightly sweet, slightly salt, taste to the stir-fry. It is also a good source of magnesium, once opened it can be kept in a cool cupboard, it does not need to be chilled.
Like many of the ingredients section I won't be showing you how to make it! We buy it, Thai's don't make these sauces at home, anymore than you make mayonnaise.