Score top and bottom of meat with a 1 1/2 inch square pattern, and score the side. Sprinkle meat liberally with unseasoned meat tenderizer, then pierce with fork 1/8 inch apart and at least half-way through the meat on both sides. Sprinkle lightly with water, and rub in tenderizer. Place on a plate, cover, and set aside for an hour.

In a small bowl, mix together oil, lemon juice, seasoned salt, lemon pepper, garlic, parsley, and tarragon vinegar. Pour marinade over meat, reserving a portion to be used for brushing (Note: DO NOT mix the reserved marinade with the meat; set aside for later). Pour remaining marinade over meat, recover dish and refrigerate for three hours, turning every half hour.

Preheat grill for hot heat.

Lightly oil grate, and position it 2 inches above the coals. Place meat on grill, and cook for 5 minutes. Turn meat over, brush with marinade, and cook for another 5 minutes.