To butterfly the chicken, using kitchen shears or a sharp knife, cut chicken down each side of the backbone. Remove the backbone. Turn chicken breast side up. Press firmly on the breastbone to flatten. Place in a flattish dish.
To make the marinade mix together Wattie’s Smoked Hickory Flavoured BBQ Sauce, orange juice, brown sugar and wholegrain mustard. Pour over chicken, ensuring both sides are covered in the marinade. Cover and refrigerate. Marinate for 1-2 hours, or can be done the day before if wished.
Preheat a lidded barbecue to 200°C.
Remove the chicken from the marinade and set the marinade aside. Place the chicken breast-side up on a rack in a tray or on a lined hotplate. Close the lid. Reduce the temperature to medium-low.
Use the remaining marinade to glaze the chicken every 20 minutes. A size 14 chicken will take 1-1 1/4 hours. Cooking time will vary according to size of chicken.
To test if the chicken is cooked. Insert a skewer into the thickest part of the meat, when the juices run clear the chicken is cooked. Allow to stand 15 minutes before carving.
If preferred the chicken can be cooked in the oven at 180°C fan bake.