Why You Should Try The French Way Of Poaching Fish

Poaching fish is a delicate way to cook a filet of fish that's tender and full of flavor without high heat, which can overcook the fragile proteins in fish. A major player in popularizing traditional French recipes, Julia Child knew to poached fish in wine for more flavor. The French method of poaching fish is known as à la nage, which roughly translates to "in the swim," and it's a quick and simple way to cook fish without overpowering it's natural flavors. This method is great for delicate fish that may be too fragile for other harsher cooking methods like grilling or pan-searing, but it's not ideal for thick, sturdy fish like swordfish or tuna.

While traditional poaching is done by fully submerging a food in water to cook it through (think of poaching eggs), the à la nage method doesn't require the filets of fish to be fully submerged in its cooking liquid. By using a wide, flat-bottomed pan with high sides, the partially immersed filets are able to cook gently through as the steam and moist heat are trapped inside the pan by a tight-fitting lid. You can poach in water, but that won't impart any flavor or seasoning into the fish. Poaching fish in a flavorful liquid will have the most impact, and there are a plethora of liquids you can add or combine to really inject the filet of fish with more flavor.

By gently cooking fish in a savory broth, which usually includes dry white wine, you have complete control over the flavor profile of the fish and can adjust according to your needs each time. For a Japanese-leaning meal, you can poach your fish in dashi or sake, and for a Thai-inspired meal, poach the fish in a liquid steeped with fresh lemongrass, ginger, and chiles. The beauty of this French poaching method, other than being healthy and simple to execute, is that you can customize the flavor of the poaching liquid to fit any recipe or cuisine you'd like. 

You can increase the depth of flavor in your poaching liquid by sautéing alliums or other vegetables beforehand, similar to cooking a mirepoix before making a soup or sauce. Since the fish cooks so quickly in the simmering liquid, it's best to simmer the broth with any aromatics or seasonings for at least 20 minutes before adding the fish to allow for the flavors to develop. Traditionally, the fish is usually served with its poaching liquid ladled on top of the dish. A healthier alternative to poaching fish in a butter sauce, you can also reduce your poaching liquid after you've removed the cooked fish for a quick way to craft a tasty sauce.