When humans first put fish to fire--back when sashimi wasn't a trend but a fact of life--it no doubt was on a stick. And it no doubt was dull. Thankfully kebabs now get properly dressed: in savory sauces and ornamental skewers, adding flair to today's gatherings.
To bathe fish in flavor, brush a marinade on the kebabs. With few exceptions, fish and shellfish are low in fat and can dry out when cooked, so the addition of butter or olive oil in the marinade keeps seafood moist and prevents flesh from sticking to grill grates. Fatty fish such as salmon or mackerel will baste in their own natural oils to offer juicy, flavorful meat.
Presentation proves as important as the prep work. Of the many skewer styles (usually wood or metal), wood or bamboo types are the most readily available and reasonably priced. Use versions 6 inches or shorter for cooking appetizers, 10 inches and longer for entrées. Of course wood burns, so soak them in water for at least 30 minutes before grilling. The natural texture of wood actually helps hold food on, but to avoid having food spin heaviest side down when you're flipping it, simply use two skewers. Most wood skewers are disposable. Reusable skewers must be washed thoroughly after use, because porous wood can trap bacteria and germs.
Metal skewers also come in many styles; flat or double-pronged metal versions work well because the food is less likely to spin. Just remember the ends remain hot after cooking. Diners should use a fork to slide the food onto a plate.
Select thick, firm-textured fish for kebabs. Popular choices include swordfish, tuna, and salmon. Purchase fish steaks so it's easy to cut cubes. If you have a thin piece, leave the skin on; it keeps the meat from falling off the skewer and peels off easily after cooking. Many fish, such as flounder and sole, are too thin and delicate for skewering. Unless prepared whole in a grill basket, they'll fall apart.
Judith M. Fertig, coauthor of Fish & Shellfish, Grilled & Smoked (Harvard Common Press, 2002), touts monkfish kebabs. "Monkfish has a lobsterlike flavor and is easy to cut into chunks," she says, noting its popularity in Spain and Portugal. Judith recommends mixing different fish on a skewer for variety, but "make sure all pieces are the same size for even cooking." Also, leave space between the fish pieces when threading ingredients. "When the fish touches the veggies," she says, "it cooks slowly and unevenly."
To keep kebabs from sticking, spray the grill grate with cooking spray or brush with oil before heating. Be sure to preheat the grill; fish is more likely to stick to a cold grate. And don't forget that loaded kebabs are unwieldy. Use tongs to turn or remove them, being careful not to crush tender seafood. If the kebabs do stick, use a metal spatula to loosen them gently.
Finally, fish kebabs are done when the flesh goes from translucent to opaque. At that point, you can see the fish start to flake. It's OK to peek with a fork or sharp knife.
Thick, firm-textured fish works best for kebabs. Here are a few ideal choices:
cusk, halibut, kingfish, mahi mahi, monkfish, salmon, yellowtail snapper, striped bass, swordfish, tuna.
Let local availability, personal taste, and recommendations from your grocer dictate substitutions.