1. Prepare Florida Harvest Salad: Combine Florida Orange Juice, Florida Orange Segments, celery root, sour cream and ¼ cup chopped parsley in medium bowl; toss to combine. Refrigerate.
2. Prepare Red Walnut Mixture: Combine walnuts, shallot, ¼ cup parsley and olive oil in small bowl; toss to combine. Season with salt and pepper to taste.
3. Preheat oven to 350° F. Place chicken breasts on sheet pan lined with parchment paper. Cook in oven for 35 minutes or until internal temperature reaches 165° F. Remove from oven and cool.
4. Slice chicken breast on the bias. Fan slices on plate. Spoon Florida Orange Harvest Salad alongside chicken breast slices. Spoon Red Walnut Mixture on top of chicken breast slices. Garnish with parsley sprigs, if desired.
*Red walnuts can be purchased at specialty supermarkets or online.