2. Cook the onions, stirring occasionally, until translucent, about 5 to 7 minutes, then lower the heat a little and continue cooking. After another 5 to 7 minutes, when the onions are golden brown, pour in the sherry vinegar, add the thyme, and stir well. Continue simmering the onions and vinegar until the majority of the liquid is gone, and the onions have turned to a brown, jamlike consistency. Remove from heat, pluck out the thyme sprigs with tongs, and let cool.
Per serving: 28 calories, 1 gram protein, 3 grams carbohydrates, 1 gram sugar, 1 gram fat, 3 milligrams cholesterol, 67 milligrams sodium, trace dietary fiber.