How to Make It
Heat the oil until it is hot but not smoking in a nonstick skillet. Add the croutons, and cook them for about 2 minutes in the oil, stirring them occasionally until they are nicely browned on all sides. Transfer the croutons to a bowl, and set them aside.
Sprinkle the fish steaks on both sides with the salt and pepper, and place them skin side down in the hot skillet you used to sauté the croutons. (No additional fat is required.) Cook the fish, uncovered, for 3 minutes over medium to high heat, then cover and cook it for another 2 minutes. Place the steaks skin side up on a warm platter, and sprinkle them with the croutons, lemon flesh pieces, capers, and chives.
Discard any fat that has accumulated in the skillet. (Jacques Pépin had 2 tablespoons of melted fat from the fish in his skillet.) Add the butter to the skillet, and cook it over medium heat until it is lightly browned. Add the vinegar, shake the pan to mix it in, then pour the mixture over the fish steaks on the platter. Serve immediately.