White Fish With Horseradish Potatoes Recipe

Cook potatoes

Place the peeled, cubed potatoes in a medium pot and cover with cold water by 1 inch. Add a pinch of salt, bring to a boil over high heat, then reduce to a simmer and cook until potatoes are very tender (about 12–15 minutes). Drain thoroughly in a colander.

Mash and season

Return drained potatoes to the pot or a warm bowl. Add the butter and begin mashing until mostly smooth. Stir in warmed milk a little at a time until you reach a creamy consistency. Fold in 2 tablespoons prepared horseradish, 3/4 tsp salt and 1/4 tsp black pepper. Taste and adjust horseradish or salt as desired. Keep warm while preparing fish. Sprinkle chopped chives or green onions over the mash before plating.

Prepare crust mixture

In a medium bowl combine the thawed, well-drained shredded hash browns (squeeze out excess moisture with a towel if needed), panko breadcrumbs, finely chopped onion, 2 tablespoons prepared horseradish, grated lemon zest, chopped parsley, 1 teaspoon salt and 1/2 teaspoon black pepper. Mix thoroughly until evenly distributed. Drizzle in 2 tablespoons olive oil and stir to moisten the mixture—this helps with browning and adhesion.

Preheat oven and prepare fish

Preheat the oven to 425°F (220°C). Line a baking sheet with parchment or lightly oil a rimmed sheet. Pat the fish fillets dry with paper towels and season both sides lightly with a pinch of salt and pepper.

Apply crust to fillets

Using your hands or a small spatula, press a generous layer of the hash brown–panko mixture onto the top (and optionally slightly down the sides) of each fillet so it adheres and forms an even crust about 1/4–1/2 inch thick. If the mixture is too loose to adhere, press it into place and chill the fillets for 10 minutes to help set the crust.

Sear (optional) and bake

For the crispest crust, heat a large ovenproof skillet over medium-high heat and add 1 tablespoon olive oil. When hot, place fillets crust-side down and sear 1–2 minutes to brown the crust (be careful not to flip and break the crust). Transfer skillet to the preheated oven and bake for 8–12 minutes, depending on fillet thickness, until the fish is opaque and flakes easily with a fork and the crust is golden. If you did not sear, bake the fillets on the prepared sheet for 12–15 minutes until cooked through and golden on top. If necessary, broil 1–2 minutes at the end to crisp and brown the crust—watch closely to avoid burning.

Rest and check

Remove fish from oven and let rest 2 minutes. The internal temperature should reach 145°F (63°C) at the thickest point. Transfer to plates alongside the horseradish mashed potatoes and garnish with lemon wedges.

Serve each fillet with a generous scoop of the horseradish mashed potatoes. Squeeze lemon over the fish just before eating. Optionally drizzle a little extra olive oil over the crust for sheen and additional flavor.