Mary Berry Fish Pie with Leeks Recipe

The standard fish pie on this site is a classic — white fish, smoked haddock, prawns, cream sauce, mashed potato. This version adds leeks, which changes the character of the dish noticeably and beautifully.

Properly softened leeks — sweet, silky, completely collapsed — give the cream sauce a gentle sweetness and a more complex flavour than a plain cream sauce.

The leek and fish combination is one of those pairings that is more established in French cooking than British but belongs entirely in a British pie.

The sweetness of the leek against the slightly smoky smoked haddock, the briny prawns, and the flaky white fish gives a filling that is more nuanced and more interesting than the plain version.

This is the fish pie I make when I want the classic but slightly more refined.

Ingredients for Mary Berry Fish Pie with Leeks

For the Fish Filling

• 300g skinless cod or haddock fillet, in large chunks
• 200g skinless smoked haddock fillet, in large chunks
• 150g large raw king prawns, peeled
• 600ml whole milk
• 1 bay leaf, 6 black peppercorns, slice of lemon

For the Leek Cream Sauce

• 50g unsalted butter
• 3 large leeks, washed and sliced into 1cm rounds
• 3 garlic cloves, crushed
• 50g plain flour
• The strained poaching milk (approximately 550ml)
• 150ml double cream
• 1 tsp Dijon mustard
• 2 tbsp fresh dill, chopped
• 2 tbsp fresh flat-leaf parsley, chopped
• Juice of ½ lemon
• Salt and freshly ground white pepper

For the Mashed Potato Top

• 1.2kg floury potatoes (Maris Piper), peeled and roughly chopped
• 100g unsalted butter
• 150ml warm whole milk or double cream
• 50g mature Cheddar, finely grated — for the top
• Salt and white pepper

How to Make Mary Berry Fish Pie with Leeks

Step 1 — Poach the Fish

Place the white fish and smoked haddock in a wide, shallow pan. Pour over the milk. Add the bay leaf, peppercorns, and lemon slice. Bring to a very gentle simmer and poach for five to six minutes until just beginning to flake. Lift out carefully. Strain and reserve the poaching milk. The prawns do not need poaching.

Step 2 — Make the Perfect Mashed Potato

Boil the potatoes in well-salted water until completely tender. Drain thoroughly. Dry in the pan over a low heat for two minutes. Pass through a ricer or mash until smooth. Beat in butter and warm milk or cream until silky. Season very generously. The mash should be slightly stiffer than eating consistency — it needs to hold its shape on top.

Step 3 — Cook the Leeks

In a large saucepan, melt the butter over a medium-low heat. Add the sliced leeks and cook for twelve to fifteen minutes, stirring occasionally, until completely soft, slightly collapsed, and beginning to turn sweet. Add the garlic and cook for two more minutes.

Step 4 — Make the Leek Cream Sauce

Sprinkle the flour over the softened leeks. Stir for one to two minutes. Add the warm poaching milk gradually, whisking continuously until smooth. Add the double cream and mustard. Bring to a gentle simmer and cook for five minutes until thick and glossy. Add the dill, parsley, and lemon juice. Season carefully — the smoked haddock will add saltiness.

Step 5 — Combine the Filling

Preheat your oven to 200°C / 180°C fan / Gas 6. Gently fold the poached white fish, smoked haddock, and raw prawns into the leek cream sauce. Transfer to a large, deep ovenproof dish approximately 30x20cm. Leave to cool for ten minutes.

Step 6 — Top and Bake

Spoon the mashed potato over the filling in generous spoonfuls, then spread evenly to cover completely. Rough up the surface with a fork to give texture that will crisp during baking. Scatter grated Cheddar over the top.

Bake for 25 to 30 minutes until the potato top is golden and the filling is bubbling at the edges. Rest five minutes before serving.

My Top Tips For Perfect Fish Pie with Leeks

Cook the leeks for twelve to fifteen minutes minimum. This is the same instruction as the chicken and leek casserole and the chicken and leek pie — because it matters equally here. Properly softened leeks are sweet, silky, and melt into the cream sauce. Undercooked leeks taste slightly harsh and slightly raw, which is the opposite of what this pie needs.

Season the sauce carefully — the smoked haddock is salty. Smoked haddock gives significant saltiness to the poaching milk and therefore to the sauce. Taste before adding any salt and add cautiously.

Cool the filling ten minutes before topping. Hot filling rising through the mash during baking can give a slightly uneven top that is harder to level and spread. Ten minutes of cooling gives a more manageable, more evenly spreadable filling.

Rough up the mash surface with a fork. The rough peaks and ridges of forked mash crisp and brown beautifully in the hot oven, giving texture contrast to the creamy filling. A smoothed mash top bakes to a uniform but less interesting golden.

The leeks in the sauce are the filling — do not add extra separately. The leeks cooked into the cream sauce give sweetness throughout every bite of the filling. They do not need to be added as a separate layer.

Serving Suggestions

With steamed peas alongside — their freshness suits the gentle leek and fish combination. With a simple green salad. On its own — this is a complete, substantial meal.

How to Store

In the fridge: Store covered for up to 2 days. Reheat covered with foil at 180°C for 25 minutes until piping hot.

In the freezer: Freeze before baking for up to 2 months. Cover tightly. Defrost overnight and bake as directed, adding ten minutes.

Mary Berry Fish Pie with Leeks Recipe

Mary Berry's fish pie with leeks adds sweet, silky leeks to the classic cream sauce — giving a gentler, more complex filling under a golden mashed potato top.

Print Recipe Pin Recipe

Prep Time 35 minutes mins

Cook Time 25 minutes mins

Total Time 1 hour hr

Servings: 6 Portions

Course: Main Course

Cuisine: British

Calories: 540

Ingredients Method Notes

Ingredients

  

• Fish Filling:
• 300 g skinless cod or haddock in large chunks
• 200 g skinless smoked haddock in large chunks
• 150 g large raw king prawns peeled
• 600 ml whole milk
• 1 bay leaf 6 peppercorns, slice of lemon
• Leek Cream Sauce:
• 50 g unsalted butter
• 3 large leeks sliced 1cm rounds
• 3 garlic cloves crushed
• 50 g plain flour
• Strained poaching milk approximately 550ml, warm
• 150 ml double cream
• 1 tsp Dijon mustard
• 2 tbsp fresh dill chopped
• 2 tbsp fresh flat-leaf parsley chopped
• Juice of ½ lemon
• Salt and white pepper
• Mashed Potato Top:
• 1.2 kg Maris Piper potatoes peeled and roughly chopped
• 100 g unsalted butter
• 150 ml warm whole milk or cream
• 50 g mature Cheddar finely grated
• Salt and white pepper

CHECK THIS RECIPE  Mary Berry Beef Wellington Recipe

Method

 

1. Poach white fish and smoked haddock in milk with bay leaf, peppercorns, and lemon — 5–6 minutes. Lift out. Strain and reserve milk.
2. Boil potatoes — drain, dry, mash until smooth. Beat in butter and warm milk. Season generously. Set aside.
3. Melt butter over medium-low heat. Cook leeks 12–15 minutes until completely soft and sweet. Add garlic — 2 minutes. Add flour — stir 1–2 minutes. Add warm poaching milk gradually — whisk smooth. Add cream and mustard. Simmer 5 minutes until thick. Add dill, parsley, and lemon juice. Season carefully.
4. Preheat oven to 200°C / 180°C fan / Gas 6. Fold fish and raw prawns into leek sauce gently. Transfer to dish. Cool 10 minutes.
5. Spoon mash over filling — spread evenly. Rough up with a fork. Scatter Cheddar over top. Bake 25–30 minutes until golden and filling bubbling. Rest 5 minutes.

Notes

Cook leeks for 12–15 minutes minimum — properly softened leeks give sweetness throughout.

Season sauce carefully — smoked haddock makes the poaching milk salty.

Cool filling 10 minutes before topping — gives a more manageable, evenly spreadable top.

Rough up the mash with a fork — the peaks crisp and brown for texture contrast.

Freeze before baking for up to 2 months.

Frequently Asked Questions

Can I add salmon to this pie?

Yes — 150g of fresh salmon fillet poached with the other fish and flaked into the filling gives a richer, more varied result.

Can I use spinach alongside the leeks?

Yes — 100g of baby spinach wilted briefly and squeezed thoroughly dry, added to the leek sauce just before the fish goes in, gives colour and freshness.

Can I use sweet potato mash for the top?

Yes — sweet potato mash gives a more golden, slightly sweeter top that suits the leek filling beautifully. Use the same quantity and method.

Why is my sauce thin?

The poaching milk was not warm enough when added to the roux, or the sauce was not simmered long enough to thicken properly. Ensure the poaching milk is warm and simmer the sauce for the full five minutes.