Rinse the chicken under cold water and pat it dry with paper towels. Remove any giblets if present.
Make the Marinade:
In a small bowl, combine the olive oil, softened butter, three cloves of finely chopped garlic, turmeric powder, chipotle powder, allspice powder, seasoning salt, cane sugar, dried thyme, lime zest, and lime juice. Mix well to create a smooth paste.
Season the Chicken:
Rub the marinade all over the chicken using your hands and coat the outside and under the skin for deeper flavor penetration. If time allows, let the chicken marinate in the refrigerator for at least 1 hour, or preferably overnight, covered.
Roasting:
Place the chicken breast side up in a roasting pan. Add the remainder of the garlic to the cavity with one whole onion. Truss the legs together with kitchen twine and tuck the wing tips under the body.
Roast in the preheated oven for about 1 hour and 15 minutes, or until the juices run clear when you cut between a leg and thigh and the internal temperature reaches 165°F (74°C).
Resting:
Remove the chicken from the oven and let it rest for about 10 minutes before carving. This helps the juices redistribute throughout the meat, ensuring it’s moist and flavorful.
Serving:
Carve the chicken, serve with fresh lime wedges, and garnish with fresh thyme sprigs if desired.