Dinner

Puffed Salmon & Spinach Fish Pie Recipe

ByNoah Steele January 17, 2026January 17, 2026

Introduction

This puffed salmon and spinach fish pie is a comforting and elegant dish that combines tender fish with creamy spinach-infused mashed potatoes. The fluffy, cheese-topped potato crust adds a delightful texture, making it perfect for a family dinner or special occasion.

A round white dish filled with a green and golden baked casserole that has a textured top layer made of melted cheese and chopped greens. A portion is scooped out, showing a creamy, white sauce inside with small shrimp and herbs, giving a contrast between the bright green top and smooth white filling. Next to the dish, a white plate has a serving of the casserole with the same layers visible, sitting on a white marbled surface with a folded cloth beneath. Four forks are placed beside the dish and plates, ready for use. photo taken with an iphone --ar 4:5 --v 7

Ingredients

1kg Maris Piper potatoes, cut into large chunks
2 large eggs, separated

400g frozen whole-leaf spinach (frozen weight), defrosted and squeezed dry
85g reduced-fat mature cheddar

Whole nutmeg, for grating
500g fish – a mix of white and salmon (e.g., 2 frozen salmon fillets and 2 cod fillets), defrosted

1 onion, halved
A few whole cloves
1 fresh or dried bay leaf

300ml semi-skimmed milk
300ml fish stock (from a cube is fine)
25g butter

2 tbsp extra-virgin olive oil
50g plain flour
1 tsp wholegrain mustard

Instructions

Step 1: Boil the potatoes in salted water for 20 minutes until tender. While the potatoes cook, place the fish in a frying pan skin-side down. Stud the onion halves with the cloves and add them to the pan along with the bay leaf, milk, and fish stock.
Step 2: Bring the liquid to a boil, then cover and simmer for 2 minutes. Remove the cod fillets once they flake easily. Re-cover the pan and cook the salmon for another 3 minutes until just cooked. Remove the salmon and set all fish aside. Strain the cooking liquid and keep it for the sauce.
Step 3: In a separate pan, melt the butter with the olive oil. Stir in the flour and cook gently for 2 minutes until it smells toasty. Remove from heat and slowly whisk in the reserved fish cooking liquid. Return the pan to heat and whisk continuously until the sauce boils and thickens.

Step 4: Stir the wholegrain mustard into the sauce, then remove from heat. Drain the cooked potatoes and mash until smooth. Beat in the egg yolks, squeezed spinach, and most of the cheddar cheese. Season generously with salt, pepper, and a grating of nutmeg.
Step 5: Whisk the egg whites to soft peaks and gently fold them into the potato mixture in two batches, preserving the airiness.
Step 6: Flake the cooked fish into a large baking dish and pour over the mustard sauce. Spread the spinach potato topping evenly over the fish. Sprinkle the remaining cheddar cheese on top.

Step 7: Bake in a preheated oven at 180°C (160°C fan, gas mark 4) for 35-40 minutes until the top is golden and puffed up. Serve warm and enjoy!

Tips & Variations

Use a mix of smoked and fresh fish for a deeper flavor.
For a richer pie, substitute some of the semi-skimmed milk with cream.

Make sure to fold the egg whites gently into the potatoes to keep the topping light and fluffy.
Spinach can be substituted with kale or silverbeet if preferred.

Storage

Store any leftovers in an airtight container in the refrigerator for up to 2 days. Reheat in a moderate oven (around 160°C) until warmed through to help maintain the texture. The topping may lose some of its puffiness after reheating but will remain delicious.

How to Serve

A white round dish holds a seafood casserole with two clear layers: the bottom layer is creamy white with visible shrimp pieces, and the top layer is a thick, bright green mix with a slightly crispy, golden-brown melted cheese crust. A wedge is cut out, showing the inside. Next to the dish is a white plate with a blue floral rim and a serving of the casserole, featuring both creamy white and green layers. A woman's hand holds a fork near the plate, and several silver forks rest on a white marbled surface next to some stacked white plates. The dish sits on a green-striped white cloth. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use fresh spinach instead of frozen?

Yes, you can use fresh spinach. Wilt it lightly in a pan, drain well, and squeeze out excess moisture before adding it to the mash.

What types of fish work best in this pie?

A combination of white fish like cod or haddock with salmon creates a nice balance of flavors. Feel free to use other firm white fish or smoked fish according to your preference.