This light fish in a lemony sauce, which always appears on Italian and French menus, has remained a favorite for decades. I served it in my first restaurant, and continue to serve it today. I recommend using fillet of sole in this recipe, but the fillet of any fish prepared this way is delicious. It is easy to prepare, and even kids love it. The result is a pucker lemon finish, with briny capers. You know how much I love olive oil, but there is a time and a place for everything. When sautéing foods that cook quickly, like these sole fillets, using some butter along with the oil help the sole brown before they overcook. Thicker sole or flounder fillets are ideal for this dish, but if yours are thinner, you may find it easier to handle them if you cut them in half first. Traditionally the fillets are simmered in the sauce, but I like to cook the sauce separately and spoon it around the sole fillets—they stay crispier that way.
5 tablespoons extra-virgin olive oil, plus more for finishing the sauce if you like
6 tablespoons unsalted butter
6 fillets gray of lemon sole, approximately 2 1/2 pounds
all-purpose flour for dredging
5 cloves garlic, peeled and crushed
12 thin lemon slices (about 2 lemons)
3 tablespoons drained tiny capers
1/4 cup freshly squeezed lemon juice
1/4 cup dry white wine
1/2 cup vegetable stock or water
2 tablespoons chopped fresh parsley
salt and freshly ground black pepper
Preheat the oven to 250 degrees F. Heat 3 tablespoons of the olive oil and 4 tablespoons of the butter in a large, heavy skillet over medium-high heat until the butter is foaming.
Dredge the fillets in the flour to coat both sides lightly, gently lay as many of the fillets into the pan as fit without touching. Cook just until the underside is lightly browned, about 4 minutes. Flip them gently with a wide metal spatula, and cook until the second side is browned and the fish is opaque in the center, about 2 minutes. Transfer them with the spatula to a baking sheet, and keep them warm in the oven. Repeat it necessary with the remaining fillets, adjusting the heat under the skillet to prevent the bits of flour in the pan from burning.
When all the sole fillets have been browned, carefully wipe out the skillet with a wad of paper towels. Add the remaining olive oil and the remaining butter and crushed garlic, and return to medium heat. When the butter is foaming, slide in the lemon slices, and cook, stirring gently, until they are sizzling and lightly browned. Stir in the capers, and heat until they are sizzling, about 1 minute. Pour in the lemon juice and wine, bring to a boil, and cook until reduced by about half. Pour in the vegetable stock, bring to a boil, and boil until the sauce is lightly thickened, about 2 minutes. If you like, drizzle in a tablespoon or two of the olive oil to enrich the sauce. Sprinkle in the parsley, and taste, seasoning with salt and pepper if you like.
Remove the sole from the oven, and set one fillet in the center of each plate. Fish the lemon slices out of the sauce, and top each fillet with two of them. Spoon the sauce around the fillets, dividing it evenly. Serve immediately.