wash chicken inside and out, drain and Pat dry with paper towels. In a large bowl, put the lemon zest and juice, garlic, salt, pepper, oregano and oil and mix to combine. Place chicken in a large pan and spoon half of the lemon mixture over the chicken and into the cavity.
Prepare kettle or hooded gas barbecue. Place potatoes and pumpkin in a large foil pan, sprinkle with remaining lemon mixture, tossing to coat. Place trays over direct heat. Cover barbecue with lid or hood and cook for 1 to 1 1/2 hours brushing chicken with lemon and herb mixture every 20 minutes. Turn vegetables
Remove vegetables when cooked, cover to keep hot. Rest chicken for five minutes before carving. Serve hot with roasted vegetables and a side salad. Serves 4 to 6.