red onions, peeled, halved lengthwise, and cut into 1/4-inch slices
dry red wine
red wine vinegar
brown sugar, packed
- Combine all the ingredients in a non-reactive pot and bring to a boil over moderate heat.
- Reduce the heat and simmer uncovered, stirring often, until the mixture is thick and has the consistency of marmalade, about 30 minutes.
- Cool and store covered in the refrigerator for up to 3 weeks.
- Makes about 2 cups.