The generic name "redfish" applies to several species also commonly known as red drum, channel bass, and bull red. As the name implies, this fish has variations of red skin coloring, but the flesh inside is white that becomes light and flaky when cooked. Redfish is often prepared on a grill, particularly through the South in areas along the Gulf Coast. Grilled redfish is commonly called redfish on the halfshell not because it has a shell, but because it's cooked with the skin and scales intact to prevent the flaky fish from falling apart on the grill.
Season the flesh and scales sides of the redfish to suit your personal taste; choices include a Cajun blackened seasoning, the milder flavor of lemon pepper, or simple salt and pepper. You can also marinate redfish for a minimum of 1 hour, using a store-bought or homemade marinade. If making your own, start with an acidic base, such as vinegar or citrus juices, add a fat, such as olive oil or melted butter and finish with your choice of herbs and spices. Place the fish in a bag or pan and cover with the marinade; refrigerate for 1 hour or overnight.
Preheat the grill to a medium heat, whether you use charcoal or a gas grill. Add water-soaked wood chips, such as mesquite, hickory, or apple wood, to impart a wood-smoked flavor on the fish, if desired.
Spray the grill rack with non-stick cooking spray, or use a paper towel to rub oil onto the rack. Do not spray cooking spray while the grill rack is on place over the fire.
Remove the fish from the marinade, if you're using it; reserve the marinade for basting. Brush both sides of the redfish with an oil or butter to keep it from sticking to the grill.
Place the redfish on the grill racks ,with the skin side facing down.
Grill the redfish for about 20 minutes or until the flesh become opaque and the thickest part flakes easily with a fork. Exact grilling times vary depending on the thickness of the fillet. Lift the grill cover every 5 to 10 minutes while grilling and brush on some of the marinade, butter or oil to keep the fish moist.
Remove the redfish from the grill, using a thin metal spatula. Scrape the spatula along the grill rack to scrape away any stuck-on parts of the fish skin. When serving redfish, you can leave the skin intact and simply eat all the meat except for the skin. If you'd rather remove the skin, slide a spatula between the meat and skin layers to separate them.
While redfish is most frequently cooked with only the skin side touching the grill rack, you can start the fish with the flesh side down and grill it for about 10 minutes to give the meat a slight char before flipping it and finishing it with the skin side down. The biggest problem with this is that soft fish meat frequently sticks to the grill racks. To avoid this, cook the meat side on individual pieces of aluminum foil with several holes poked in the foil. When it's time to flip the fish, flip it along with the foil and peel the foil off of the fish.