Caramelized Red Onion Relish

Caramelized Red Onion Relish

Prep Time: 5 minutes
Cook Time: 80 minutes
Servings: 8
The tart-sweet quality of crème de cassis, or black currant liqueur, reinforces the sweetness of the onions as they brown, while its purple-red color boosts the natural hue of the onions. Once opened, a bottle of cassis will keep for many months and is a nice addition to both pantry and bar. A nonalcoholic version of cassis is also available.


  • 8 Tbs. (1 stick) unsalted butter
  • 8 lb. red onions (about 10 large), halved
     and thinly sliced
  • 2 tsp. salt, plus more, to taste
  • 1⁄3 cup firmly packed light brown sugar
  • 1⁄3 cup crème de cassis
  • 1⁄3 cup red wine vinegar
  • 1 Tbs. minced fresh thyme or 1 1⁄2 tsp. dried
  • Freshly ground pepper, to taste


In a very large fry pan over medium heat, melt 4 Tbs. (1/2 stick) of the butter. Add half of the onions and 1 tsp. of the salt. Cover and cook, stirring occasionally, until the onions are tender and have rendered some of their liquid, about 15 minutes. Transfer to a bowl. Repeat with the remaining 4 Tbs. (1/2 stick) butter, the remaining onions and the remaining 1 tsp. salt.

Return the first batch of onions and any juices from their bowl to the fry pan. Stir in the brown sugar and cassis, and then add the vinegar. Cook over low heat, stirring and tossing frequently, until the onion juices have evaporated, about 30 minutes. Continue to cook, uncovered, stirring occasionally, until the onions are tender and lightly browned, 20 to 30 minutes more.

Stir in the thyme and season with pepper. Taste and adjust the seasonings with salt. Serve hot. Serves 8 to 10.

Make-Ahead Tip: The relish can be prepared up to 3 days in advance. Let cool, cover and refrigerate, then rewarm it over low heat just before serving.
Adapted from Williams-Sonoma Collection Series, Thanksgiving, by Michael McLaughlin (Simon & Schuster, 2001).