Preheat your oven to 400°F (200°C) and prepare a roasting pan by lightly greasing it with a little oil.

In a small mixing bowl, combine the olive oil, minced garlic, harissa paste, cumin, coriander, lemon zest, lemon juice, salt, and black pepper to create a thick marinade.

Pat the chicken completely dry with paper towels, ensuring the skin is free of moisture to help it crisp up during roasting.

Gently loosen the skin from the breast meat and rub the softened butter underneath the skin, then coat the entire chicken thoroughly with the spicy garlic marinade, massaging it into the meat and inside the cavity.

Place the chicken breast-side up in the roasting pan and roast for 75 minutes, basting with the pan juices every 20 minutes to keep the meat moist.

Check for doneness by inserting a meat thermometer into the thickest part of the thigh; it should read 165°F (74°C) and the juices should run clear.

Remove the chicken from the oven and let it rest for at least 10 minutes before carving to allow the juices to redistribute.

Garnish with fresh chopped parsley and serve warm with the pan drippings spooned over the meat.