Mr. Steven Raichlen on
HOW TO GRILL THE PERFECT FISH STEAK:
Start with a very fresh fish. If you like it rare in the center (like in the case of tuna), cut the steak 1-2 inches thick. If you like it cooked through, cut the steaks 1/2 inch thick. When grilling salmon steaks, leave the bones in. They help hold the fish together.
Preheat the grill to high. When ready to cook, brush the fish steaks on both sides with oil or melted butter & season with salt & pepper. If you have previouly marinated the fish in a mixture rich with oil, butter or coconut milk, it is unnecessary to either blot dry, further oil or season. The grate should be oiled, however; the fish can go on the grate right after you have done that.
Arrange the fish steaks on the hot grate, all facing in the same direction. Cover the grill & cook the fish steaks on one side for about 2 minutes for a 1/2 inch steak; 4-6 minutes for steaks 1 or more inches thick. If desired, after 2 minutes, using a long spatula, rotate the steaks about 90 degrees to create an attractive crosshatch of grill marks.
Carefully turn the steaks over, using the spatula, & cook the other side in the same way.
The Barbecue Bible by Steven Raichlen, P. 317