Turn on grill to high heat and allow it to heat for 5-10 minutes until very hot. (If using a charcoal grill, heat up the grill for around 10-15 minutes with the lid on. If the charcoal barbecue is not hot enough, make sure the lid vents are open fully.)
Rinse the fish and lay it onto paper towels. Use the paper towels to pat the fish dry and place the fillets on a wire rack (a baking or cooling rack placed inside of a baking sheet works great to catch any drips and spills).
Sprinkle half the salt and half the pepper over the fish. Carefully drizzle half of the olive oil over the seasoned fish. Using a pastry brush or your fingers, evenly distribute the oil all over that side of the fish.
Flip the fish over on the rack and repeat with remaining salt, pepper, and oil. Let the fish rest and marinade until the grill is hot.
Use a brush to scrape the grill grate clean and then lower the grill temperature to low. If using a charcoal grill, reduce the temperature by closing the air dampers to 1/4 open.
Place the fish on the grill, close the lid, and leave the fish to cook with the lid closed, without turning for 7 to 10 minutes (chances are really good your fish will be done right at 7 minutes unless it is very thick, so check it at 7 minutes!).
The fish should be white and flaky when tested with a paring knife and reach an internal temperature of 150°F. Using a metal spatula remove the fish fillets from the grill.
Sprinkle with additional kosher salt (to taste) and lemon juice, and then serve with additional lemon slices and chopped parsley to suit individual tastes.
Notes
You can use this cooking method for just about any firm white fish, such as catfish, tilapia, pollock, and cod.
The trick for perfect grilled fish is to cook in a pre-heated grill at low heat, with the lid closedwithout turning until cooked.
The first squeeze of lemon isn’t optional, but additional lemon and parsley can be served as optional garnishes.
When looking for the highest-quality fish, search for FAS, Frozen at Sea, or Individually Quick-Frozen (IQF).