Poached fish is a simple and delicious dish that can be prepared quickly and easily. Poaching is a good technique for cooking lean fish like tilapia, cod, sole, haddock, snapper or halibut, as well as fatty fish like salmon or trout.

Poaching preserves moisture and adds flavor without adding fat — though you may want to serve poached fish with a sauce. The method shown here calls for making a simple velouté sauce from the poaching liquid.

Alternately, you can prepare a basic White Wine Sauce in advance to serve with the poached fish. For more sauce ideas, here's a list of sauces for fish and seafood.

As for the poaching liquid itself, I like to prepare a simple court bouillon, which is a flavorful, aromatic, slightly acidic liquid that really adds a lot of flavor to the fish without overpowering it. Here's a basic court bouillon recipe.

Here's How:

1. Prepare 1 gallon of court bouillon. If poaching a whole fish, allow court bouillon to cool. For fillets or other small portions, the poaching liquid should be hot.
    
2. Make a series of shallow, diagonal cuts on the skin side of the fish fillets. These cuts prevent the fillet from curling during the poaching process. You can poach the fillets flat or fold them in half (skin-side in).
    
3. If you're poaching a whole fish, place the fish in the cold court bouillon and then bring it to a simmer. The liquid should fully cover the fish.
    
4. Otherwise (for fillets or other small portions), heat the court bouillon to a simmer in a stockpot or soup pot. When the liquid reaches 160°F as measured with an instant read thermometer, gently add the fish to the liquid. The liquid should fully cover the fish. Don't let it boil; the liquid should remain between 160°F and 180°F. At the proper temperature, you should see very few bubbles.
    

1. Cook for about five minutes or until the fish is just done without being overcooked. Carefully remove the fish. If your sauce is already prepared, transfer fish to a plate, coat with sauce and serve. If you plan to prepare a velouté from the cooking liquid, keep the fish covered and warm while you do the next step.
    
2. Transfer about four cups of the poaching liquid to a separate saucepan. Reduce by about half, then whisk the resulting liquid into a simple butter-flour roux to make a velouté sauce. Sauce the fish and serve right away.

Tips:

1. Instead of a court bouillon, you can poach fish in a mixture of half fish stock, half white wine. Just make sure there is enough liquid to cover the fish.
    
2. When poaching a whole fish such as a trout, wrap it in cheesecloth so that it doesn't curl while cooking.
    
3. As an alternative to the diagonal cuts technique described in step 2, you can roll the fillets into little spirals called paupiettes. Start at the large end and roll the fillet toward the tip, making sure the skin is on the inside of the roll.
    
4. Instead of poaching in a stockpot or soup pot, you can use a special fish poacher with a rack for holding the fish. This lets you easily remove the fish from the poaching liquid without damaging it. The fish poacher's long, narrow shape makes poaching whole fish easier, and also lets you poach in the oven for even heating.