Remove turkey from refrigerator and allow it to come to room temperature for about 1 hour before grilling. This ensures even cooking.

In a small bowl, combine olive oil, salt, pepper, thyme, garlic powder, and paprika to create a seasoning paste.

Gently separate the skin from the meat without tearing it, and rub about half of the seasoning mixture directly onto the meat under the skin. Rub the remaining mixture over the outside of the turkey.

Stuff the turkey cavity with lemon quarters, onion, and rosemary sprigs.

Preheat your gas grill for indirect heat cooking. Turn one side of the burners on medium-high heat (around 350-400°F) and leave the other side off. This creates an 'oven' effect.

Place a drip pan on the unlit side of the grill, filling it halfway with water to catch drippings and create moisture.

Lightly oil the grill grates on the unlit side.

Position the turkey breast-side up over the drip pan on the unlit side of the grill.

Close the grill lid and maintain a consistent temperature between 325-350°F throughout cooking.

Grill for approximately 15-18 minutes per pound (about 3 hours for a 12-pound turkey), or until a meat thermometer inserted into the thickest part of the thigh reads 165°F.

Check the turkey every 45 minutes, adding more water to the drip pan if needed to prevent it from drying out.

If the turkey skin browns too quickly, loosely tent it with aluminum foil.

Once the turkey reaches 165°F in the thigh and 160°F in the breast, remove it from the grill.

Tent with foil and let rest for at least 20-30 minutes before carving to allow juices to redistribute.