Preheat the oven to 400ºF. Lightly grease a roasting pan and place a wire rack in the base of the pan.
Trim any excess fat from the chicken and discard the neck. Rinse the chicken (including the cavity) under cold running water and pat dry with paper towel. Season the cavity with sea salt and freshly ground black pepper.
Using a fork or metal skewer, prick the lemon all over and place inside the chicken cavity. Rub the oil all over the outside of the chicken and season well. Roast the chicken for 45 minutes–1 hour, or until the juices run clear when the thigh is pierced with a knife. Remove from the oven and allow to rest, covered, for 10 minutes before serving.
Serve the roast chicken with orange sweet potato, the steamed broccoli or a green salad.