For Eva Casal-Mendez, cooking honors the deep connection between the ocean, the land, and the rhythm of the seasons. Originally from Galicia on Spain’s Atlantic coast, she first visited the East End in 2019 and fell in love with Sag Harbor. Fall remains her favorite season on the South Fork, as the changing colors, crisp coastal air, and bountiful local harvest remind her of her native Spanish home.
In her forthcoming book, Soleré: The Sherry Vinegar Cookbook, Casal-Mendez explores the versatility of sherry vinegar across roughly 100 recipes. Now, most of us stateside home cooks are thinking: sherry vinegar? On this side of the Atlantic, we usually relegate vinegar to a quick salad splash or let a dusty bottle sit in the back of the pantry until Thanksgiving rolls around. But over in Spain, it’s practically a religion — and once you see what it does to a roasting pan, you’ll understand why.
A native of Galicia, Eva Casal-Mendez is more than accustomed to celebrating coastally inspired cuisine. (Photo credit: Doug Young)
In this classic whole-fish preparation, a preview recipe graciously shared by Casal-Mendez, local fluke is roasted directly over patatas panaderas (Spanish-style roasted potatoes with sweet onions, garlic, and red pepper). As the fish roasts, its tender flesh stays exquisitely moist while its juices drip down into the potatoes below, creating a rich sauce that the sherry vinegar, a Spanish secret weapon, brings brilliantly to life.
“Growing up in Galicia, I am accustomed to eating whole roasted fish, particularly rodaballo (turbot),” Casal-Mendez says. “While local fluke is a different species, its delicate flesh lends itself beautifully to the same Spanish tradition of roasting fish whole over a bed of potatoes. It’s a dish that brings together two Atlantic coastlines I love: Galicia and the Hamptons.”
Early autumn is prime time for East End fluke. During September and October, baitfish fill the back bays and ocean washes, prompting fluke to feed aggressively before heading offshore — making late fall the ultimate window for landing trophy-sized local fish. For local sourcing, pick up a whole fresh fluke at Out of the Blue seafood market in Hampton Bays, and grab rich Yukon Gold potatoes from Marilee and Dean Foster at Sagaponack Potato Company (Foster Farm), where six generations of family heritage keep potato farming alive on the South Fork.
Inspired by two coastal towns she loves — her home and Sag Harbor — Casal-Mendez’s whole roasted fluke with patatas panaderas lends itself well for celebrating East End bounty, easily utilizing locally caught fluke and Sagaponack potatoes. (Photo credit: Doug Young)
This is your sign to go ahead and pull that bottle of sherry vinegar out from the back corner of your pantry — or better yet, invest in a proper Spanish bottle. Using it twice — first to bake depth into the potatoes, then at the end to turn humble pan drippings into liquid gold — will make you wonder why you ever limited vinegar to salad dressings in the first place. Consider your weeknight roasting routine officially upgraded.
Tips for the Home Cook
- Don’t Rush the Potatoes: The secret to patatas panaderas is giving the potatoes a head start. Make sure they are almost fully cooked, tender, and starting to caramelize at the edges before you place the fish on top.
- Keep the Pan Moist: Check the roasting pan before adding the fluke. If the liquid has evaporated, add a splash more stock or water to ensure the potatoes absorb the fish juices without drying out or scorching.
- Two-Stage Sherry Vinegar: Adding sherry vinegar in two stages is key. The first tablespoon seasons and builds deep flavor as the potatoes bake, while the final tablespoon, drizzled at the end, preserves a bright, fresh pop of acidity.
- Easy Whole-Fish Carving: Don’t let a whole fish intimidate you! The diagonal slashes made before roasting make serving effortless. Use a wide spatula to lift the top fillets away from the backbone, lift and discard the main bone, and scoop out the bottom fillets along with a generous helping of the pan-dripping potatoes.
Whole roasted fluke with patatas Panaderas & sherry vinegar
Ingredients
- 1 whole local fluke (or lemon sole), ~2 lbs. cleaned and gutted with head and tail intact
- 1 1/2 lbs Yukon Gold potatoes, sliced into ⅓-inch rounds
- 1 large sweet onion, thinly sliced
- 4 garlic cloves, thinly sliced (divided)
- 1/2 red bell pepper, thinly sliced
- 1/4 cup extra-virgin olive oil, plus extra for rubbing and finishing
- 1/2 cup dry white wine (ideally Fino or Manzanilla sherry)
- 1/2 cup fish stock or water (divided, plus extra if needed)
- 2 tbsp sherry vinegar (divided)
- 1/2 tsp sweet Spanish paprika
- 2 tbsp finely chopped flat-leaf parsley (divided)
- fine sea salt and freshly ground black pepper, to taste
Directions
- Prepare the Potatoes: Preheat your oven to 425°F. Arrange the sliced potatoes, onion, red pepper, and most of the sliced garlic in a large roasting pan (reserving a small amount of garlic for the fish). Add the paprika, 3 tablespoons olive oil, 1 tablespoon sherry vinegar, the white wine, and ¼ cup fish stock. Season generously with sea salt and black pepper, toss well to coat, and spread into an even, slightly overlapping layer.
- Roast the Potatoes: Cover the pan tightly with aluminum foil and bake for 25 minutes. Remove the foil, gently turn the potatoes, and return to the oven uncovered for another 15–20 minutes, until nearly tender and turning golden around the edges.
- Prep the Fluke: While the potatoes bake, pat the fluke dry with paper towels. Using a sharp knife, make 3–4 diagonal slashes through the dark skin into the flesh almost down to the backbone. Season generously inside and out with salt and pepper. Rub the skin with a little olive oil, then tuck the reserved garlic and 1 tablespoon of the chopped parsley directly into the cuts.
- Roast the Fish: Check the potatoes. If the pan seems dry, pour in the remaining ¼ cup of stock. Place the fluke directly on the potato bed and spoon a bit of pan juices over it. Roast uncovered for about 25 minutes (check early to prevent overcooking), until the flesh is opaque, separates easily from the bone, and reaches 145°F at its thickest point.
- Finish and Serve: Remove the pan from the oven and drizzle that final tablespoon of sherry vinegar into the hot juices surrounding the potatoes. Spoon the glossy roasting juices over the potatoes and fish, scatter with the remaining parsley, and finish with a light drizzle of extra-virgin olive oil. Serve warm straight from the pan, lifting the tender fillets away from the bone and pairing each portion with a generous serving of pan-dripping potatoes.
