Slice up the lemon and combine it in a food processor with the parsley, olive oil and pepper. Blitz it together, leaving it finely chopped as opposed to pureed. Transfer to an extra large plastic sealable bag, add the chicken and rub it around in the marinade. Squeeze out as much air as possible, seal tight and refrigerate for 2-3 hours.
Pre-heat your bbq to medium heat with the lid closed. Once smoking, scrub it clean, lightly oil with some canola. Keep the lid close until your are ready to get grillin'.
Remove the chicken from the marinade (discard the marinade), rub off the excess, season it all over with salt and pepper and set it on the grill skin side down, close the lid, reduce the heat to medium low and let cook for 5 minutes, watch out for flare ups.
Gently turn the chicken over, close the lid and reduce the heat to medium low. Let the chicken cook for another 30-35 minutes, and it has reached an internal temperature of 170°F (77°C) in the thickest part of the bird.
Remove the chicken from the grill and let it rest for 10 minutes, while you get the table ready. Cut the chicken into eights; 2 drums, 2 thighs, and 2 breasts cut in 2 pieces each and serve garnished with slices of grilled lemon and fresh parsley.