Whisk marinade ingredients in a small bowl.
Rub the marinade all over the chicken, then place it all in a large resealable bag. Marinate chicken in the fridge for up to 24 hours.
Preheat the oven at 350F. Place the chicken with all the marinade juices in a roasting tray together with potatoes, carrots, parsnip, and fresh rosemary sprigs. Roast for 1.30 to 2 hours or until the thigh juices run clear when tested with a skewer.
When the chicken is done, place it in a new dish, cover with aluminium foil and let it rest for 15 minutes before carving.