From Wikibooks, open books for an open world
Roman Sauce (Salsa Agro-dolce)
Variant One 
- Mix two spoonfuls of burnt sugar with one of vinegar, and dilute with a little good stock.
- Then add two cups of Espagnole sauce, a few stoned raisins, and a few pinocchi (pine nuts) or shredded almonds.
- Keep this hot in a bain-marie, and serve with cutlets, calf's head or feet or tongue.
Variant Two 
Roman Sauce (another way)
- Cut up a small bit of onion, fry it slightly in butter and a little flour, add the juice of a lemon and a little of the peel grated, a bouquet of herbs, a pinch of nutmeg, a few stoned raisins, shredded almonds or pinocchi, and a tablespoonful of burnt sugar.
- Add this to a good Espagnole sauce, and warm it up in a bain-marie.
This page incorporates text from the public domain cookbook The Cook's Decameron: A Study In Taste, Containing Over Two Hundred Recipes For Italian Dishes.