If using charcoal grill, place drip pan directly under grilling area, and arrange coals around edge of firebox. Heat coals or gas grill for indirect heat. Loosen skin on turkey in 4 or 5 places. Carefully place lemon slices and basil leaves under skin. Rub turkey skin with oil; sprinkle with lemon-pepper seasoning. Insert barbecue meat thermometer so tip is in thickest part of turkey.