America's Test Kitchen Fish Pie Recipe: Creamy Mashed Potato Topping Over Flaky Pastry

America's Test Kitchen fish pie delivers restaurant-quality comfort in every bite—creamy mashed potato topping over a rich, flaky pastry crust. This recipe transforms simple ingredients into a foolproof dish that's perfect for pescatarian meals or family dinners.

The secret lies in balancing textures: tender fish filling, velvety mashed potatoes, and a golden, crispy top layer that seals in all the flavors.

What sets this fish pie apart is the precision of America's Test Kitchen methods. We start with a flavorful fish filling—whether you choose white fish, shellfish, or crab—coated in a rich béchamel sauce that binds everything together.

The mashed potato topping isn't just a garnish; it's the star, blending buttery potatoes with cream and cheese for a silky, cohesive finish. Every layer is designed to work in harmony, ensuring no bite feels dry or underseasoned.

The baking process is where the magic happens. At 375°F, the pie develops a flaky, golden crust while keeping the filling tender and the mashed potatoes creamy—no soggy tops here. The result? A dish that looks impressive but requires no fancy techniques, just careful layering and patience.

This is the kind of recipe that transforms a simple weeknight into a memorable meal, with every forkful offering a perfect balance of textures and flavors.

Serve with a crisp green salad or steamed vegetables to round out the meal. The leftovers reheat beautifully, making this an ideal dish for meal prep or entertaining. Whether you're a seasoned home cook or just starting out, this fish pie delivers restaurant-quality results with simple, reliable steps.

Let's get started on creating your own perfect slice of comfort.

Ingredients for america's test kitchen fish pie

Sixteen ingredients transform into a restaurant-quality fish pie with creamy mashed potato topping and flaky crust.

The fish is your canvas—cod, haddock, or halibut work best for their mild flavor and firm texture. Whole Foods or your local seafood market are ideal for fresh fillets, but frozen works too (thaw overnight in the fridge). For that béchamel sauce, Land O'Lakes heavy cream gives the richest texture, but any full-fat brand will do. The butter must be cold when making the roux—this is non-negotiable for a smooth sauce. If you're feeling ambitious, a homemade pie crust elevates the dish, but a quality store-bought crust (like Pepperidge Farm) saves time without sacrificing flakiness. The Russet potatoes should be waxy, not starchy—look for firm, unblemished tubers at Trader Joe's or your grocery store's produce section.

No fresh dill? Dried dill at one-third the amount works in a pinch, but fresh is worth hunting down—it brightens the filling beautifully. Running short on sharp cheddar? Parmesan or Gruyère add depth, though the flavor shifts slightly. The lemon juice can be swapped for white wine vinegar if you're out, but fresh lemon adds a zesty punch. For the pie crust, if you're making it from scratch, European-style butter (like Plugrá) creates superior flakiness. No pie crust at all? A thin layer of mashed potatoes pressed on top can work as a makeshift crust, though it won't be as golden. The egg wash is optional but gives that golden finish—beat it with a splash of milk for extra shine.

This pie reheats like a dream—375°F for 15-20 minutes until bubbly and golden. Store leftovers in an airtight container for up to 4 days in the fridge, or freeze for 3 months (wrap tightly in foil first). The mashed potato topping can be prepped ahead and refrigerated separately, then spread over the filling before baking. For meal prep, assemble the pie up to a day ahead and refrigerate—it'll taste even better after the flavors meld overnight. The crust stays crispy if you reheat it covered with foil for the first 10 minutes, then uncovered to brown.

Step-by-step instructions for america's Test Kitchen fish pie

This classic comfort dish delivers tender fish, velvety mashed potatoes, and a golden crust every time.

Preheat your oven to 375°F for the baking stage. In a large oven-safe skillet, melt 2 tablespoons of the unsalted butter over medium heat. Add the finely diced yellow onion and cook for 5-6 minutes until soft and translucent, stirring occasionally. Add the minced garlic cloves and cook for 30 seconds until fragrant—don't let it brown or it'll turn bitter.

Push the onions and garlic to one side of the pan and add the white fish fillets. Season immediately with 1 teaspoon of the salt and ¼ teaspoon of the ground white pepper. Cook the fish for 3-4 minutes per side until it's just opaque in the center and flakes easily with a fork. Remove the fish and set it aside on a plate, leaving the aromatics in the pan.

Deglaze the pan with the lemon juice, scraping up any browned bits from the bottom. Stir in the heavy cream and whole milk, then return the fish to the pan. Simmer gently for 2 minutes until the sauce thickens slightly. Remove from heat and stir in the chopped fresh dill and remaining ½ teaspoon of salt. The filling should be creamy but not watery—this is your flavor base.

While the fish filling cooks, prepare the potatoes. Peel and cut the russet potatoes into 1-inch chunks and place them in a large pot of cold salted water. Bring to a boil and cook for 15-20 minutes until fork-tender. Drain thoroughly and return to the pot.

Add the shredded sharp cheddar cheese and the remaining ¼ cup of cold unsalted butter. Mash vigorously with a potato masher or ricer until completely smooth and creamy. The texture should be velvety with no lumps—this is what makes our pie stand out. If needed, add 1-2 tablespoons of the reserved pasta water to reach the perfect consistency.

Transfer the mashed potatoes to a mixing bowl and fold in the remaining ½ teaspoon of ground white pepper. The pepper adds a subtle elegance that complements the fish perfectly. Spread this mixture evenly over the fish filling in the skillet, creating a smooth, even layer that will create a beautiful crust when baked.

Roll out the store-bought pie crust on a lightly floured surface to fit the skillet. Carefully transfer it to cover the mashed potato topping, pressing gently along the edges to seal. Use a sharp knife to trim any excess dough. Cut a few small slits in the top to allow steam to escape—this prevents a soggy crust.

Brush the crust with the beaten large egg for a golden finish. Bake in the preheated 375°F oven for 30-35 minutes until the crust is deep golden brown and the filling is bubbling at the edges. The crust should be crisp while the filling remains creamy inside—this is the perfect balance of textures.

Remove from the oven and let rest for 10 minutes before serving. The resting time allows the juices to redistribute, ensuring each bite is moist and flavorful. Serve with a simple green salad or steamed vegetables to complete the meal—this pie is rich enough to stand alone but pairs beautifully with fresh accompaniments.

Perfect pairings for these flavors

Classic Side Pairings

Start with a simple arugula salad dressed with 1 tablespoon lemon juice, 2 tablespoons olive oil, and a pinch of flaky sea salt. The peppery greens cut through the richness of the fish pie beautifully.

For a heartier option, serve with steamed asparagus tossed with 1 teaspoon lemon zest and a sprinkle of toasted almonds for crunch. 🥗

Wine Pairings

A crisp Sauvignon Blanc from New Zealand—like Kim Crawford—complements the lemon and dill flavors perfectly. The wine’s bright acidity balances the creamy mashed potatoes and rich fish filling.

For a red option, try a light Pinot Noir from Oregon, such as Domaine Serene, which won’t overpower the delicate flavors. 🍷

Beer Pairings

An English pale ale, like Fuller’s ESB, pairs wonderfully with the fish pie’s savory and creamy elements. The beer’s malty sweetness and subtle hop bitterness enhance the dish’s depth.

For a lighter option, a Belgian witbier such as Stella Artois adds a refreshing citrus note that mirrors the lemon in the filling. 🍺

Bread and Garnishes

Serve with crusty sourdough bread or baguette slices for soaking up any extra sauce. For garnishes, add a sprinkle of fresh parsley or chives right before serving to brighten the dish. A drizzle of truffle oil (just ½ teaspoon) adds a luxurious touch if you’re feeling indulgent. ✨

Seasonal Vegetable Additions

In spring, add sautéed spring peas and thinly sliced radishes for freshness. For fall, roasted carrots and brussels sprouts with a touch of maple glaze create a cozy contrast. These additions keep the meal balanced and visually appealing year-round. 🌿

Dessert Pairings

Finish the meal with a light lemon posset or vanilla panna cotta to cleanse the palate. For a classic option, crème brûlée with its caramelized sugar top adds a sweet contrast to the savory pie. A simple berry compote with whipped cream also works beautifully. 🍋

Frequently asked questions