Combine marinade ingredients in a bowl and stir until thoroughly mixed. Marinade the turkey breast fillet in the marinade mixture overnight in the refrigerator.
Preheat BBQ or grill plate to medium heat. Place the turkey breast on the grill with the skin side down. Grill for approximately 20 minutes on each side. We recommend using a meat thermometer to check that the turkey has reached at least 76°C in the thickest part of the fillet.
Allow to rest for 10 minutes before slicing.