In a stainless steel or glass bowl, combine garlic, olive oil, basil, salt, pepper, lemon juice, and parsley. Place the halibut fillets in a shallow glass dish or a reusable plastic bag and pour the marinade over the fish. Cover or seal and place in the refrigerator for 1 hour, turning occasionally. Preheat an outdoor grill for high heat and lightly oil grate. Set grate 4 inches from the heat. Remove halibut from marinade and drain off the excess. Grill 5 minutes per side or until fish is done when easily flaked with a fork.