1. Heat your oven to 180°C/Fan 160°C/Gas 4. Fire up the barbecue if you’re using it. Unwrap the chicken and pat it dry. Set aside to come up to room temperature.
2. Grate or pare the zest from the lemon. Juice it. Tip into a pestle and mortar. Peel and grate or crush the garlic. Add to the lemon zest and juice along with the spices, a glug of oil and 1 tsp salt. Bash to form a paste.
3. To spatchcock the chicken, stand it up and gently pop out the shoulder joints. Use a sharp knife or scissors to cut either side of the backbone along through the ribs. Remove the backbone and save it for adding to stock with the giblets and the carcass.
4. Flip the bird over and press down to flatten it. Thread a skewer diagonally through the thigh, breast and wing. Repeat on the other side. Using wooden skewers? Soak them in water first to stop them burning.
5. Pop the chicken, skin-side up, in a roasting dish. Rub the marinade all over the chicken. Slide into the oven to roast for 20 mins.
6. If finishing the chicken on the barbecue, remove it from the oven after 20 mins. Pour any juices and spices that have run into the tin out into a small jug. Lay the chicken on the hot barbecue and cook for15-20 mins on each side till cooked through, basting it regularly with the saved juices, topped up with a little beer if you like.
7. If finishing the chicken in the oven, leave the juices in the tin and let it roast for 30-40 mins total, basting regularly, till it's cooked through.
8. To check if the barbecued or roast chicken is cooked through, insert a skewer into the thigh. The juices should run clear. If not, barbecue or roast the bird till they do.
9. Leave the cooked chicken to rest, covered with foil, for 20 mins before serving.