Ingredients

  • 1 small red onion, chopped (1/2 cup)
  • 1 (14- to 16-oz) can whole tomatoes in juice, including juice
  • 1 cup fresh or frozen cranberries, coarsely chopped in a food processor
  • 2/3 cup sugar
  • 1/3 cup cider vinegar
  • 2 (4- by 1-inch) strips fresh orange zest
  • 1 (4- by 1-inch) strip fresh lemon zest
  • 1/4 teaspoon dried hot red pepper flakes, or to taste
  • 1/8 teaspoon salt

Method

  • Bring all ingredients to a boil in a 2-quart heavy nonreactive saucepan over moderate heat, stirring and breaking up tomatoes.
  • Reduce heat and simmer, uncovered, stirring frequently, until thick, 20 to 25 minutes.
  • Cool preserves, then chill, covered, at least 8 hours (for flavors to develop).