Gastrique
Gastrique is caramelized
sugar, deglazed with
vinegar, used as a flavoring for sauces.
To this a little fond (stock) may be added. It is used to flavor sauces such as
tomato sauce, savory fruit sauces, and other sweet and sour sauces such as the classic orange sauce for duck à l'orange.
Nowadays the term is frequently used to refer to any thus-flavored sauce itself, e.g. citrus gastrique, mango gastrique.
An agrodolce (sweet and sour) is a similar sauce found in Italian cuisine.
