When ready to cook halibut, heat gas or charcoal grill. When grill is heated, lightly oil grill rack. Remove halibut from marinade; discard marinade. Place halibut on gas grill over medium heat or on charcoal grill over medium coals; cover grill. Cook 10 to 14 minutes, turning once, until fish flakes easily with fork. Garnish with lemon slices and fresh greens, if desired.