In Italy, this dish would be prepared with rombo (turbot), but flounder is certainly an excellent substitute. Flounder is a flakier fish and will cook quicker, so either cut the potatoes into slightly thinner wedges, or boil them a minute or two longer. The flounder you choose for this dish should be a thick one. The dark skin is removed while the white is left on the bottom so the fish does not fall apart when it is being served.
Recipe information
Yield
Makes 4 servings
Ingredients
Preparation
Step 1
Clean the turbot, cut off the head, and peel off the dark skin, but leave the tails, fins, and white skin intact. (Or ask your fishmonger to do this for you.)
Step 2
Heat a large saucepan of salted water to the boil. Peel the potatoes, cut them in half, and cut the halves into 1-inch wedges. Cook the wedges in the boiling water until starting to soften, about 5 minutes. Drain the potatoes and toss them in a bowl with the onions and 2 tablespoons olive oil. Season with salt and pepper and toss again.
Step 3
Preheat the oven to 425° F. Choose a wide roasting pan large enough to hold the whole turbot, potatoes, and onions in a single layer. Season the turbot generously with salt and pepper and brush the bottom of the roasting pan with the remaining olive oil. Place the turbot skin side down in the center of the pan, and arrange the potatoes and onions around the turbot. Distribute the rosemary evenly around the pan.
Step 4
Roast until the fish is opaque at the thickest part and the potatoes are golden brown, about 30 minutes. To make sure the potatoes and onions cook and brown evenly, remove the pan from the oven and turn the potatoes and onions.
Step 5
To serve, divide the fish into four fillets as follows: Run a small knife along the center of the top fillet down to the bone, following the dark line that runs along the center of the top of the fish. Wiggle the knife along the cut to separate the top half of the fish into two fillets. Slide a small metal spatula between the top fillets and the bone and transfer them to a warm platter. Check the fillets; they should be relatively bone-free. You are now left with the bottom fillet, entirely covered by the skeleton. You can remove most of the bones in one piece if you lift gently, starting at the tail end. Scrape any remaining bones from the fillets with a spoon, paying special attention to the bones around the edges. Divide the bottom half of the fish into two fillets, as you did the top half. Transfer them to the platter—with or without the skin—and flank all the fillets with the roasted potatoes and onions. Drizzle the fish and vegetables with extra-virgin olive oil and serve immediately.
