Ingredients:
3 medium yellow onions (about 1 1/2 pounds), sliced into thin half-moons
1 cup sherry vinegar or white-wine vinegar
1/2 cup dry white wine
1/4 cup granulated sugar
1 tablespoon finely chopped fresh thyme
Kosher salt and ground white pepper

Instructions:
In a 4-quart or larger non-reactive saucepan, combine the onions, vinegar, wine, 1/2 cup water, sugar, and thyme. Bring to a boil over high heat; reduce the heat to medium low and simmer slowly, stirring occasionally, until the onions are very soft and the liquid has cooked down to a syrupy consistency, 45 minutes to 1 1/4 hours. The onions should be fairly moist but not swimming in syrup. Taste and season with salt and pepper and adjust the sugar and acid level as necessary to get a sweet-and-sour flavor. Let cool, transfer to an airtight container, and refrigerate for up to two weeks.

No of Servings:
about 2 1/2 cups