Seafood Fish Pie Recipe: Buttery Mashed Potato Crust Over Flaky Pastry Layers

This seafood fish pie recipe delivers the ultimate comfort food experience—where tender fish, rich béchamel, and buttery mashed potato crust come together in perfect harmony. 🌟 I first perfected this version during a rainy Portland winter when I needed something hearty enough to warm up a chilly kitchen and elegant enough to impress guests.

The secret lies in the layers: flaky puff pastry on top and creamy mashed potatoes at the bottom, with a velvety seafood filling that melts in your mouth.

The filling starts with fresh, lightly poached fish and shrimp in a delicate white wine and herb broth, then thickened with a smooth béchamel sauce that binds everything together.

While the traditional approach uses store-bought puff pastry, I've included a foolproof homemade mashed potato crust variation that adds extra richness and a satisfying texture contrast. The result? A pie that's crisp on top, creamy in the middle, and packed with flavor in every bite.

What makes this recipe truly special is how it balances tradition with simplicity—no fancy techniques required, just precise timing and attention to detail. The aroma of baking fish pie fills the kitchen with warmth, while the golden crust and bubbling filling create a visual masterpiece.

Whether you're serving it as a centerpiece for dinner parties or a cozy family meal, this recipe delivers restaurant-quality results with minimal effort.

For an extra touch, I recommend garnishing with fresh parsley and a drizzle of lemon butter before serving. The bright acidity cuts through the richness, adding a final layer of sophistication. Let's bring this classic dish to life in your kitchen—your taste buds will thank you.

Ingredients for seafood fish pie

Six layers of comfort—creamy mashed potatoes, flaky pastry, and tender seafood that melts in your mouth.

The fish and shrimp are the heart of this pie, so freshness is key. Hit the seafood counter early—look for cod or haddock with a bright, clean smell and firm texture. Whole Foods or local fish markets often have the freshest selections, but the frozen section at Trader Joe's works in a pinch (just thaw overnight). Shrimp should be plump and snap back when bent. For the white wine, grab a dry Sauvignon Blanc—Kim Crawford or Oyster Bay are reliable choices. The butter? Plugrá or Land O'Lakes work, but European-style unsalted (like Kerrygold) adds extra richness.

No white wine? Fish or chicken stock with a splash of lemon juice mimics the acidity perfectly. Swapping fish for shrimp? Use 1.5 lbs shrimp and skip the fish fillets—just adjust cooking time slightly. The béchamel can be made ahead (it actually tastes better the next day), so prep it the night before if you're short on time. For the mashed potatoes, Russet potatoes are ideal—their starchiness makes them ultra-creamy. If you're using homemade puff pastry, keep it cold until you're ready to roll it out—warm dough gets sticky fast.

Assemble the pie 2 hours before baking—this gives the filling time to chill and the crust to set. Store leftovers in the fridge for 3-4 days, or freeze portions for up to 3 months. The mashed potato crust reheats beautifully, so cover with foil to prevent over-browning. Garnish with fresh parsley and lemon butter right before serving—the bright acidity cuts through the richness and makes it feel restaurant-worthy. Leftovers taste even better the next day, so plan ahead!

Step-by-step instructions for seafood fish pie with flaky layers

Here's how to build layers of golden pastry and creamy filling that deliver perfect flakiness every time.

Heat 0.25 cup unsalted butter in a large skillet over medium heat until melted. Add the 2 whole minced shallots and 4 cloves minced garlic, cooking for 2-3 minutes until soft and fragrant—you should smell the garlic blooming. Add the 1.5 lb fish fillets and 1 lb shrimp, cooking just until the shrimp turn pink and the fish flakes easily (3-4 minutes).

Remove the seafood and set aside. In the same pan, pour in the 0.5 cup white wine and scrape up any browned bits with a wooden spoon. Let it simmer for 2 minutes until reduced by half. Stir in the 1 cup heavy cream, 1 tbsp Dijon mustard, 1.5 tsp salt, and 0.5 tsp black pepper. Return the seafood to the pan and warm through for 1 minute. Finish with the juice and zest of the 1 whole lemon and 0.25 cup chopped fresh parsley.

While the filling cools slightly, boil the 2 lbs peeled russet potatoes in salted water until fork-tender (15-20 minutes). Drain well and return to the pot. Add the 0.5 cup unsalted butter and 0.25 cup milk, then mash until smooth. For extra creaminess, press the potatoes through a ricer or fine-mesh sieve. Fold in 0.5 tsp black pepper and 0.5 tsp salt to taste.

Here's the thing—this mashed potato layer needs to be perfectly smooth and lump-free to create that beautiful flaky texture when baked. If you see any lumps, keep working them out with a potato masher or whisk. Spread the mashed potatoes evenly in a 9x13-inch baking dish, creating a base layer about ½-inch thick.

Spread the seafood filling evenly over the mashed potato layer, creating an even top layer. The filling should be about ½-inch thick—if it's too thick, press it down gently with a spatula. Roll out the 1 sheet puff pastry on a lightly floured surface until it's about ⅛-inch thick. Cut it to fit the baking dish with a ½-inch overhang on all sides.

Gently lift the puff pastry and place it over the filling, pressing lightly to adhere. Trim the excess pastry, leaving a ½-inch border. Use a fork to crimp the edges, creating a decorative pattern. Brush the top with a beaten egg wash (1 egg + 1 tbsp water) for that golden finish. Here's where it gets fun—make a few small slits in the pastry top to let steam escape during baking.

Preheat your oven to 400°F. Place the pie on a baking sheet (to catch any drips) and bake for 25-30 minutes until the pastry is deep golden brown and puffed in places. The filling should be bubbling gently at the edges. If the pastry browns too quickly, tent it loosely with foil after 15 minutes to prevent burning.

Let the pie rest for 10 minutes before serving—this gives the filling time to set slightly and makes slicing easier. The result should be flaky, golden layers with a creamy seafood filling that's rich but not watery. Each bite delivers that perfect combination of crispy pastry, creamy potatoes, and tender seafood.

Serving suggestions for leftovers

Crispy Garnishes

Top your fish pie with toasted breadcrumbs for a satisfying crunch—just toss ¼ cup panko with 1 tbsp melted butter and ½ tsp smoked paprika, then sprinkle over the pie before baking.

For extra flair, add crispy fried shallots (sauté 2 thinly sliced shallots in 1 tbsp butter until golden) or crumbled bacon for a smoky depth. 🌟

Bright Accents

Finish with lemon butter sauce—mix 2 tbsp softened butter with 1 tbsp lemon juice and 1 tsp chopped parsley, then drizzle tableside. The acidity cuts through the richness, balancing the creamy filling.

For a pop of color, scatter edible flowers (like nasturtiums) or microgreens—they add freshness and visual appeal. I love using Portland farmers market herbs for this touch.

Crunchy Sides

Serve with crispy roasted potatoes—toss 1 lb baby potatoes with 1 tbsp olive oil, 1 tsp rosemary, and ½ tsp salt, then roast at 425°F for 25 minutes.

Another winner: buttery green beans sautéed with garlic and almond slivers for texture. These sides mirror the pie’s richness while adding freshness. 🥔

Wine Pairings

A dry Riesling (like Dr. Loosen Blue Slate) complements the seafood’s brininess and the wine’s acidity cuts through the creaminess. For red lovers, a light Pinot Noir (such as Oregon’s Domaine Serene) balances the dish’s richness. Serve slightly chilled—45-50°F—to enhance the flavors. 🍷

Make-Ahead Magic

Assemble the pie up to 24 hours ahead and refrigerate uncovered—this helps the crust crisp up. Bake straight from the fridge (add 5-10 minutes to the baking time). For leftovers, reheat at 350°F for 15 minutes with a splash of milk to restore creaminess.

I always make extra for Tom’s lunch the next day—he swears it’s better reheated! ⏰

Frequently asked questions