Agrodolce
A saucepan of onion with agrodolce sauce
Agrodolce is a traditional sweet and sour sauce in Italian cuisine. Its name comes from "agro" (sour) and "dolce" (sweet). Agrodolce is made by reducing sour and sweet elements, traditionally vinegar and sugar. Sometimes, additional flavorings are added, such as wine, fruit, or even chocolate. It can be used for lamb, and served over rigatoni or wide noodles, such as pappardelle.
Though the term "aigre-doux" could refer to any sweet and sour sauce in French cuisine, a gastrique is very similar to agrodolce.[1]