Halibut is notoriously difficult to grill due to its low fat content. The brining process helps solve that problem, but there are a few more tricks as well.
First, don't overcook it. Halibut is best when cooked to a low internal temperature. It will readily flake at only 118 degrees, the equivalent of a rare steak.
Also, before grilling, brush a super-fine veil of homemade, or if you must, store-bought mayonnaise on both sides of the fish. This will help keep it from sticking to the grill. Do this and your days of scraping fish off the grill are over, I guarantee it.
Depending on your taste for salt, you may want to lightly season each portion with a pinch after the mayo has been applied. I also recommend a well-distributed pinch of Espelette or cayenne pepper. This helps the fish color a lovely bronze hue. At Providence, we use a dredger (a shaker for sprinkling flour) with a mesh screen to help us more evenly season meats.
Also, be sure to start with a clean grill. Heat the grill and clean it well with a wire brush. Just before putting the fish on the grill, wipe down the grate with an old rag that has been briefly dipped in cooking oil.
Cook the fish on one side for a minute or so, then mark the fillets by turning them 45 degrees, then wait another minute before flipping. I suggest using a roasting fork in your dominant hand to lift the fish from the grates and a spatula in your other hand to get beneath the fillet. Allow the fish to cook for another two minutes on the second side.
Finally, let the fish rest in a warm spot, preferably on a rack, for a minimum of five minutes. Proper resting ensures that the fish will be heated through without being cooked through.
The flesh should yield to gentle pressure when pressed. You can also use a cake tester to test the doneness of the fillet. When the fish is properly cooked, a cake tester will pass through with only gentle resistance.
—Michael CimarustiCopyright © 2015, Los Angeles Times