Preheat your oven to 180°C/Fan 160°C/Gas 4 or fire up the barbecue if you’re using it. Take the chicken from its wrapping. Pat dry. Let it get to room temperature.
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, 1 tbsp oil and 1 tsp salt. Muddle to form a paste.
To spatchcock your chicken, stand it up. 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 for adding to stock with the giblets and the carcass.
Flip the bird over and press down firmly. 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.
Pop the chicken, skin side up, into a roasting dish. Rub the marinade all over the chicken. Place in the oven for 20 mins.
Remove the chicken from the oven. Pour any juices and spices that have run from the chicken into a small jug.
Place the chicken on a hot barbecue. Cook for 15-20 mins on each side till cooked through. Insert a skewer into the thigh. The juices should run clear. If not, cook till they do. Baste the chicken regularly with the saved juices, topped up with a little beer if you like.
If you're not barbecuing, cook the chicken for 50 mins-1 hr in the oven, basting regularly. Leave to rest, covered, for 20 mins before serving.