- 3 pounds cipolline onions, stem and root ends trimmed
- 1/2 cup chicken stock or canned low-sodium broth
- 1/2 cup water
- 3 tablespoons unsalted butter
- 1 tablespoon white wine vinegar
- 1 tablespoon sugar
- 1/4 cup Cognac
- 1 cup pitted prunes
- 40 cooked and peeled unsweetened chestnuts (from a vacuum-packed 16-ounce jar)
- Salt and freshly ground pepper
- 2 tablespoons finely chopped flat-leaf parsley
- Bring a large saucepan of water to a boil. Add the onions and blanch for 30 seconds. Drain in a colander under cold running water. Slip off the papery skins and pat the onions dry.
- In a large, deep skillet, combine the chicken stock with the water, butter, vinegar and sugar. Cover and bring to a boil. Add the onions, cover and cook over moderately low heat until crisp-tender, about 15 minutes. Uncover and cook over moderate heat, stirring occasionally, until the onions are covered with a deep-golden caramel, about 30 minutes longer; add a few tablespoons of water as the liquid evaporates.
- Add the Cognac, prunes and chestnuts to the onions and cook just until heated through. Season with salt and pepper and transfer to a serving bowl. Add 2 tablespoons of water to the skillet and scrape up any caramel stuck to the bottom and sides. Pour the sauce over the onions, garnish with the parsley and serve.