Heat oven to 400*. Grease a 9 x 13 baking dish. Place chicken breast halves in greased dish. Bake for 25 minutes. Meanwhile in medium skillet over medium heat cook and stir onion in hot oil until crisp-tender. Add catsup, brown sugar, and orange zest; blend until brown sugar is dissolved. Stir in cranberries. Spoon over partially cooked chicken. Bake an additional 20 minutes or until chicken is tender.