This technique is not only simple to learn, but also incredibly quick. Often, a home cook with basic equipment can produce a perfectly cooked, elegant looking piece of fish in under 10 minutes. Sautéing provides a base for adding an almost endless array of flavors and since you are looking at the fish from start to finish, you will notice if it is going off the rails. Here is sautéing in its most basic form. You can definitely layer in flavors as you get comfortable with the technique.
Start with a boneless, skinless fish fillet. Striped bass is a very forgiving choice. Branzino works beautifully as well. Most firm white fish will work, as will salmon. I would avoid very delicate fish like sole or tai snapper as they will fall apart if you aren’t careful. Heat about a tablespoon of olive oil over medium high heat in a small skillet. When the oil starts to shimmer, place your fish in the pan. You want the fish to be sizzling gently, but it shouldn’t be an inferno. Cook for about 3 minutes adjusting the heat as necessary to keep that gentle sizzle.
Season the fish with a pinch of salt and flip it gently. I like to use a wide spatula and tilt the pan slightly toward me to soften the flip. Add about 2 tablespoons of unsalted butter to the pan.
The butter should melt and then start to foam up a bit and the solids will separate from the oil. The solids will start to brown. Browning is normal but if the butter starts to smoke or you think it is starting to burn, reduce the heat. After the butter starts to brown, tilt the pan slightly so that the butter pools on one side. Use a spoon to scoop up butter and pour it over the fish. Baste the fish with butter a few times over the next 3 minutes and then start checking the fish for doneness.
If you want the fish to be pretty on the plate, handle it gently and insert a fork into the middle of the thickest part. Pry the fish gently and look in between the flakes. If it is opaque all the way through and the color has changed, it is done. If you don’t care what it looks like, you can just break it in half and look at the middle. Salt to taste after the last baste and serve it as quickly as possible after it is done.
For a basic sauté, that’s all you need to do. You’ll have a simply cooked, beautiful piece of fish that highlights the flavors of the fish, but adds in some butter fat to make it extra satisfying and tasty. The brown butter solids add a nice level of color and texture to the surface of the fish. Once you have a basic understanding of this technique, you can start layering in flavors. Start by adding diced onion, or a diced shallot to the olive oil at the beginning. Let that caramelize in the pan for a few minutes before you lay down your fish fillet. Then when you flip the fish, top it with a couple of sprigs of thyme. Keep the thyme on the fish while you baste with butter. Try to get as much of the flavor of the herb into the fish by basting more often and pressing the thyme down gently.
For another flavor profile, start with garlic in the olive oil and cook it until it starts to brown. Add the fish and cook for 3 minutes on each side, then deglaze the pan with ½ cup of dry white wine. Add the butter and then a tablespoon of lemon juice and salt and pepper. Baste the fish just like in the original technique until it is done. You could omit the garlic and lemon and instead add some soy sauce and ginger, or omit the wine and use a little chicken stock. It is all about building depth of flavor. Play around with this simple technique and add things that you like. If you really want to step up the flavors make the garlic and wine version and when the fish is ready, put it on a plate. Add a couple shakes of Worcestershire and a few tablespoons of cream. Mix that with everything in the pan and reduce for a couple of minutes and you’ll have a quick lemon butter pan sauce.