You can use 8-inch or longer metal or wooden skewers for this dish. If you use wooden skewers, soak them in water to cover for an hour or so before threading the ingredients onto them. That should help prevent the skewers from burning as they cook. If you are using fresh bay leaves or rosemary, you can use the thin branches from either herb as skewers, flavoring the ingredients even more. Because these branches will be shorter than store-bought skewers, you will probably need to make more and smaller skewers. Also, handle them carefully as they cook—herb branches aren’t quite as sturdy as metal or wooden skewers.
A cast-iron or other heavy griddle is ideal for preparing these swordfish skewers on the stovetop. Brush the griddle lightly with olive oil and heat over medium-high heat. Cook the skewers, turning them as necessary, until well browned on all sides, about 1 minute per side. Brush an even coat of the balsamic reduction over each side, then grill another minute, turning the skewers frequently—the balsamic reduction will burn if left too long on one side.
