1. With kitchen scissors or sharp knife, cut chicken along each side of backbone (discard backbone or save for making broth). Place chicken, skin side up, on work surface; press down firmly on breastbone to flatten. Brush skin with oil; sprinkle with pepper, garlic, the 1/2 cup sage, and the orange peel. Cover and marinate in the refrigerator 4 hours or overnight.
2. Remove chicken from refrigerator 30 minutes before roasting. Heat oven to 400 degree F. Carefully place chicken, skin side up, on rack in shallow roasting pan. Sprinkle with salt. Roast 15 minutes. Pour wine over chicken and roast 30 minutes more, basting with pan juices every 10 minutes. If juices begin to evaporate, add 1/2 cup water to pan. Turn chicken over and roast 15 to 20 minutes more or until an instant-read thermometer inserted in thigh registers 180 degrees F.
3. Serve chicken on warm platter. Sprinkle on any sage leaves that have fallen off during roasting. Garnish with fresh sage leaves, if desired. Makes 6 servings.