01 - In a bowl, whisk together olive oil, lemon zest, lemon juice, garlic, oregano, salt, and pepper until fully combined.
02 - Place the spatchcocked chicken in a large dish or resealable bag. Pour the marinade over the chicken, ensuring it is well coated. Cover and refrigerate for at least 2 hours, or overnight for best flavor.
03 - Preheat your barbecue to medium (approximately 375°F) for indirect cooking, or preheat your oven if roasting indoors.
04 - Remove the chicken from the marinade and let excess drip off. Discard leftover marinade.
05 - Place the chicken skin side up on the cooler side of the grill (indirect heat). Close the lid and cook for 40–45 minutes, turning once or twice, until the internal temperature reaches 165°F at the thickest part.
06 - For crispy skin, finish the chicken skin side down over direct heat for 2–3 minutes until golden and lightly charred.
07 - Transfer to a cutting board, tent loosely with foil, and rest for 10 minutes before carving.
08 - Serve with lemon wedges and fresh oregano sprigs.