FISH FILLETS AND STEAKS

WE WANTED TO ESTABLISH A CONSIS tent method for cooking fish. While most fish must be cooked in a blazing hot pan to promote browning, we quickly realized that a thick salmon fillet with skin on could not be treated like a thin, skinless piece of flounder.

After much testing, we eventually divided boneless fish into three categories: white-fleshed fillets (everything from sole and flounder to cod and snapper), steaks (tuna and swordfish), and salmon fillets (which have their own unique cooking challenges). We developed a number of sauces that work well with all three classes of fish. The cooking issues, however, are distinct. Here are our findings.

When sautéing very thin fillets, first make sure that your pan can properly accommodate the fish. The fillets should lie flat and uncrowded in the pan. In our testing, if a piece of fish snuck up the cooler, ungreased side of the pan, it stuck and fell apart when flipped over. Because some flat fish fillets can be quite large, it is better to cut them before cooking so they lie flat. Another trick you can use to fit fillets that taper down to a thin tail and to avoid overcooking the thinner portion is to fold the tail over the main portion of the fillet so the piece is all of the same thickness.

To keep the fillets from sticking, shake the pan occasionally before flipping them. If a fillet does stick, don't scrape it off the bottom of the pan; instead, let it cook a bit longer. We found that most often the fish sticks because it hasn't had a chance to form its protective crust. Once the crust is formed, it will shake loose.

Once you turn the fillets, really thin pieces (less than ¹/₂ inch thick) will finish cooking by absorbing the residual heat in the pan, so turn off the heat source. Thicker fillets need more time, but we found it best to turn the heat to medium-high to lessen splattering and prevent scorching.

To see if the fish is done, poke it with your finger. It should feel firm but not flake. If the fish falls into dry flakes, it has been overcooked.

Sautéing thick fish steaks raises different issues. Tuna and swordfish steaks are usually sold in large, 16-ounce pieces that can be hard to cook evenly. By the time the heat reaches the center, the edges have overcooked. Cutting the steaks in half minimizes this problem. Even with steaks that were one inch thick, we found that the heat distributed more evenly through narrower pieces. An 8-ounce steak also makes an ideal single serving.

While we found that white fish fillets benefited from a dusting of flour, which helped them brown and produced a nice thick crust, we found that steaks were better left unfloured. The sturdy nature of the flesh and the longer cooking time encourage plenty of browning.

With its skin on, salmon raises other issues. We wondered if it needed as much fat. We started with two tablespoons—the amount we used to sauté white fish fillets. The results were greasy. We then cut back to one tablespoon—the amount we used to sauté tuna and salmon steaks. We thought there was too much splattering. Eventually, we found that one teaspoon of fat is sufficient to cook four salmon fillets.

As with other pieces of fish, we preheated the pan until it was very hot and tried cooking over high heat. Billows of smoke soon filled the kitchen. We found that preheating on high was fine but that the heat had to be turned down to medium-high once the fish was added to the pan.