Pan-Seared White Fish with Hasselback Potatoes and Herb Sauce
This is the kind of dinner that looks polished enough for guests but stays friendly for a weeknight cook. Thin-sliced potatoes roast until crisp at the edges and tender in the center, white fish sears quickly in a hot skillet, and a simple yellow herb sauce ties everything together with brightness.
Recipe at a glance
- Yield: 4 servings
- Prep time: 25 minutes
- Cook time: 35 minutes
- Total time: 1 hour
Ingredients
- 4 medium Yukon Gold potatoes, scrubbed
- 3 tablespoons olive oil, divided
- 1 teaspoon kosher salt, plus more to taste
- 1/2 teaspoon black pepper, plus more to taste
- 2 tablespoons unsalted butter, melted
- 4 skinless white fish fillets, about 5 to 6 ounces each, such as cod, halibut, haddock, or pollock
- 1/2 teaspoon garlic powder
- 1/2 teaspoon smoked paprika
- 2 tablespoons all-purpose flour, optional for a light crust
- 1 tablespoon neutral oil, for the fish
- 2 tablespoons mayonnaise
- 2 tablespoons plain Greek yogurt or sour cream
- 1 tablespoon lemon juice
- 1 teaspoon Dijon mustard
- 2 tablespoons chopped parsley
- 1 tablespoon chopped dill or chives
- 1 to 2 teaspoons warm water, if needed to thin the sauce
- Lemon wedges, for serving
- Extra herb sprigs, for garnish
Instructions
- Heat the oven. Set the oven to 425°F. Line a sheet pan with parchment or foil for easier cleanup.
- Prepare the potatoes. Place one potato between two chopsticks or wooden spoon handles. Slice thin, even cuts across the top, stopping when the knife hits the guides so the potato stays intact. Repeat with the remaining potatoes.
- Season and roast. Set the potatoes on the pan. Brush with 2 tablespoons olive oil, then sprinkle with 1/2 teaspoon salt and 1/4 teaspoon pepper. Roast for 20 minutes.
- Finish the potatoes. Stir the melted butter with the remaining 1 tablespoon olive oil. Brush or drizzle over the potatoes, gently encouraging some of the slices to separate. Roast 15 to 20 minutes more, until the edges are browned and crisp and a skewer slips into the center with little resistance.
- Mix the sauce. In a small bowl, stir together the mayonnaise, yogurt, lemon juice, Dijon, parsley, dill, and a pinch of salt and pepper. Add a teaspoon or two of warm water if you want a looser spoonable sauce. Taste and adjust the lemon or salt. The sauce should taste bright and creamy.
- Season the fish. Pat the fish fillets very dry. Season both sides with the remaining 1/2 teaspoon salt, the remaining 1/4 teaspoon pepper, garlic powder, and smoked paprika. If you want a light crust, dust the tops lightly with flour and shake off the excess.
- Sear the fish. Heat the neutral oil in a large skillet over medium-high heat until shimmering. Add the fish presentation-side down if one side looks better, and cook 3 to 4 minutes without moving it, until the bottom is golden and the fish releases easily.
- Flip and finish. Turn the fillets carefully and cook 1 to 3 minutes more, depending on thickness, until the fish is opaque and flakes easily with a fork. For the cleanest texture, pull it just as it turns opaque all the way through. Avoid overcooking; white fish dries out quickly.
- Plate. Spoon a little sauce onto each plate. Add a potato and a fish fillet. Spoon more sauce alongside or over the fish, then finish with herb sprigs and lemon wedges.
Tips, serving ideas, and variations
For the crispiest potato edges, keep the slices close together but not cut all the way through. If the potato starts to tilt while roasting, nestle it into a little crumpled foil so it stays steady.
You can swap in cod, halibut, haddock, or another firm white fish. If your fillets are very thick, lower the heat slightly after the flip so the centers cook through before the exterior browns too much.
To round out the plate, add a simple green vegetable such as steamed green beans, sautéed spinach, or a small salad with lemon vinaigrette. The sauce also works well with asparagus or roasted carrots.
If you prefer a dairy-free sauce, replace the yogurt or sour cream with more mayonnaise and thin with a little water and extra lemon juice.
Storage notes
Store leftover fish and potatoes separately in airtight containers. Refrigerate within 2 hours of cooking, or within 1 hour if the room is very warm. For best quality, use leftovers within 2 to 3 days. Reheat the potatoes in a 400°F oven or air fryer until warmed through and re-crisped. Reheat the fish gently in a low oven or microwave at short intervals so it does not dry out. The sauce can be chilled separately and stirred before serving.
For food safety, cook fish until it flakes easily and reaches a safe internal temperature of 145°F, as recommended by Nutrition.gov and other U.S. food-safety guidance. Keep raw seafood refrigerated, use clean utensils, and wash hands and surfaces after handling it.
