SERVES 4 TO 6
The most sublime of all of the fishes in the sea! The greenish, almost round flatfish, with a tiny mouth and eyes pinched together on top of the head, has succulent meat bursting with concentrated flavors. The best turbot are caught in the Atlantic off Europe, especially in the Bay of Biscay. When buying, try to find one of these.
The best way I have discovered to prepare them is on a bed of potatoes and onions in the oven with a good drizzle of Txakoli. Txakoli is a Basque white wine with lovely acidic notes and some natural bubbles. It is consumed very young—its optimal drinking season runs November to March, following the harvest. Happily, this season coincides with that of turbot. (You can also substitute another young, fruity white wine.) The wine gives only a slight flavor to the fish—its main function here is to seep down into the potatoes and, as it cooks, moisten and gently flavor the fish with its vapors.
1. Preheat the oven to 425°F/220°C/gas mark 7.
2. Peel the potatoes and cut into ¼-inch-½>-cm-thick slices. Soak them in a large bowl of cold water for 1 hour to leach out some of the starches. Drain, rinse, and then let drain well.
3. In a rimmed baking sheet or large roasting pan that can comfortably fit the fish, toss the potatoes and onions with the olive oil, season with salt, and spread them evenly across the tray. Cover with aluminum foil. Bake until they begin to soften, about 30 minutes. Uncover and bake for 10 minutes more, or until the edges are beginning to brown.
4. Meanwhile, make (or ask your fishmonger to do this when buying) three or four deep crosswise cuts through the central section of the fish (including spine), leaving at least 1 inch/2.5 cm of the fish uncut (thus remaining “joined”) around the edges. This will allow the fish to cook evenly, keep its shape for presentation, and be easier to serve. Generously season with salt and pepper.
5. Place the fish on top of the bed of potatoes, pour over the wine, and bake until the fish is just opaque throughout, 15 to 30 minutes, depending on its size. Test for doneness along the backbone with the tip of a knife; the meat should be just opaque and still very moist.
6. Separate the pieces of fish and divide among plates with the potatoes. Serve with extra-virgin olive oil to drizzle over as desired.