How to Make It
Preheat oven to 425°. Pat fish dry with paper towels, and let stand at room temperature 10 minutes. Sprinkle fillets with salt and pepper.
Heat oil in a large ovenproof skillet over medium-high heat. Carefully place fillets, top side down, in hot oil. Cook 3 to 4 minutes or until the edges are lightly browned. Transfer skillet to oven.
Bake at 425° for 4 to 5 minutes or until fish is opaque. Remove skillet from oven, and place fish, seared side up, on a platter.
Wipe skillet clean. Cook butter in skillet over medium heat 2 to 2 1/2 minutes or until butter begins to turn golden brown. Pour butter into a small bowl. Whisk in vinegar, shallot, and lemon juice. Season with salt and pepper.
SEARING IS BEST FOR: Nearly any type of fish, but is easiest with firm fillets that are at least 1 1/2 inches thick, such as grouper, halibut, sea bass, and striped bass.
EXPERT ADVICE: Make sure the pan is hot before adding fish. Press very lightly with a spatula while cooking for even searing.