Preheat the oven to 425 degrees . Season the chicken inside and out with salt and pepper; place it on a rack in a roasting pan. Stuff the cavity with the lemon, onion and herb sprigs; tie the legs together with kitchen string. Rub 2 tbsp. EVOO over the chicken. Roast 15 minutes.
Meanwhile, in a large bowl, combine the potatoes, carrots and rutabaga. Drizzle with 2 tbsp. EVOO; season and toss. Remove the pan from the oven. Arrange the vegetables underneath the rack. Return the pan to the oven and roast until the juices run clear when the thickest part of the thigh is pierced with a small knife, about 1 hour more. Transfer to a platter; let rest 15 minutes. Toss the vegetables with the pan juices and parsley. Carve the chicken; serve with the vegetables and pan juices.