This dish is beloved in Rome, where it pairs beautifully with roasted meats like porchetta.
Sweet and Sour Onions (Cipolline in Agrodolce)
This Roman dish of cipolline or pearl onions, caramelized and doused in a balsamic glaze, is a natural side dish for roasted pork, beef, or lamb.
1⁄2 cup raisins
3 tbsp. extra-virgin olive oil
1 1⁄2 lb. cipolline or pearl onions, peeled
1⁄4 cup balsamic vinegar
1 1⁄2 tbsp. sugar
Kosher salt, to taste
Put raisins into a small bowl; cover with hot water and let soften for 30 minutes.
Heat oil in a 12" skillet over medium-high heat. Add onions and cook until golden brown, 8–10 minutes; pour off oil. Drain raisins. Add raisins, vinegar, and sugar and season with salt. Cook, stirring, until sauce thickens, 2–3 minutes.