Meanwhile, in 10-inch skillet, heat oil over medium heat. Add onions, salt and pepper; cook 3 to 5 minutes, stirring frequently, or until onions are tender. Add chicken broth and balsamic vinegar; cook 12 to 17 minutes or until sauce is reduced by half. Stir in red raspberry and apricot preserves; cook 2 to 3 minutes, stirring frequently, or until slightly thickened. Cool 5 minutes.