sweet and sour
Agrodolce sauce in its simplest form is made from reducing vinegar and sugar, often with the addition of fruit or wine. It's often seen in Sicily (agruduci), where it was said to have been introduced by the Arabs.
It's a common way of preserving vegetables (peppers, cucumbers, onions, artichoke hearts, cauliflower) for antipasto—a sottaceto (pickle), only a little bit sweet. Innumerable recipes for poultry, fish, meats (especially rabbit) and vegetables use an agrodolce sauce.