Mackerel is one example of the fatty fish the American Heart Association recommends eating two or more times per week. It provides protein, unsaturated fats and other nutrients with fewer calories and less saturated fat and cholesterol than red meats. These qualities make mackerel -- especially when baked or grilled -- part of a heart-healthy diet. Like other fatty fish, mackerel has a pronounced, rich flavor, but it's versatile enough to support an array of recipes and side dishes. When you're grilling mackerel fillets, make sure they're completely defrosted first by keeping them in the refrigerator for at least one full day beforehand.
Rinse the mackerel fillets under cold water. Blot them dry gently but thoroughly with clean paper towels.
Marinate or season the mackerel to taste, or per the directions in a favorite fish recipe. For an easy flavoring option, brush the mackerel with a cooking oil, squirt some lemon or lime juice over it, and sprinkle on salt and pepper to taste. For a simple Asian-inflected grilled mackerel marinade, combine in a glass baking dish 1 tbsp. of olive or canola oil, 2 tsp. of rice vinegar, 1 tbsp. of soy sauce and 1 tsp. of fresh minced ginger. Put the mackerel in the dish, cover it with plastic wrap and refrigerate it for one to four hours, turning it over once halfway through.
Scrape the grill clean with a wire brush to prevent adding unpleasant flavors to the mackerel. Grease the grill with cooking oil and preheat it to high heat.
Remove the mackerel from the marinade if you used one and let the excess drip off the fillets. Discard the marinade, because it's been contaminated by raw fish.
Lay the mackerel fillets gently on the grill, skin-side up at first to develop an attractive grill pattern on the skinless side. Leave the lid open to limit the heat and prevent overcooking, which happens quickly with fish.
Flip the mackerel over with tongs or a spatula after four minutes. Grill it for an additional four minutes with the lid still open.
Remove the mackerel fillets from the grill once their flesh is opaque all the way to their center. The fish should flake apart readily with light pressure from a fork. Grill the mackerel for another minute or so as needed.