Add enough stock to come 3 cm up the side of the chicken. Place in the oven and bake 1 to 1.5 hours, or until a meat thermometer inserted in the thigh registers 180 degrees. Transfer the chicken to a cutting board and let sit 10 minutes before carving. Add any remaining stock to the pan and bring to the boil over medium-high heat, stirring and scraping the cooked bits from the bottom of the pan. Add the remaining orange peel -chopped rosemary, and half teaspoon paprika; season to taste with salt and pepper. Continue to boil until the sauce is reduced by about one-third, about 5 to 10 minutes. Arrange the carved chicken on a serving platter and pass a bowl of the sauce separately.