Step 1 Preheat oven to 180°C. Place potatoes on a baking tray and spray with oil. Set aside.
Step 2 Insert lemon pieces into chicken cavity. Place chicken in the centre of a piece of foil double the size of the chicken and place in a large roasting tray.
Step 3 Mix stock with apple juice and tomato and barbecue sauces.
Step 4 Wrap foil loosely around chicken to make a ‘bag’ in which air can circulate. Pour liquid into bag over chicken, add herbs and half the seasoning and seal bag tightly. Place potatoes on the top shelf of the oven, chicken below, and bake for 1 1/2 hours.
Step 5 Remove chicken and potatoes. Cover potatoes with foil and keep warm. Unwrap chicken carefully (steam will come out) and return chicken to roasting tray with all the juices. Discard foil. Sprinkle with remaining seasoning and baste with juices. Cook for a further 30 minutes, basting several times during cooking. Add garlic bulbs, if desired.
Step 6 Rest chicken before serving. Garnish with parsley, and serve with potatoes, steamed vegies and basting juices as gravy.