Name: Mary Berry Fish Pie With Leeks Recipe
Prep time: 25 min
Cook time: 50 min
Total time: 1 h 15 min
Ingredients: 450g skinless boneless white fish fillets such as cod or haddock cut into large chunks; 150g undyed smoked haddock cut into chunks; 200g raw king prawns peeled; 2 medium leeks trimmed washed and sliced into 1cm rounds; 30g unsalted butter; 1 small onion finely chopped; 2 tablespoons plain flour; 350ml whole milk; 100ml fish stock; 2 tablespoons double cream; 1 tablespoon flat-leaf parsley finely chopped; 1 teaspoon Dijon mustard; salt and freshly ground black pepper; 800g floury potatoes such as Maris Piper peeled and cut into chunks; 50g unsalted butter; 60ml whole milk warmed; salt and white pepper; 30g mature cheddar finely grated optional for the topping

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Mary Berry fish pie with leeks is a deeply comforting dish, with a golden, creamy mashed potato crust hiding a silky white sauce filled with tender flakes of fish and soft, buttery leeks beneath. The sauce is smooth and savoury, with just enough richness to coat every piece without feeling heavy on the palate.

This version keeps things straightforward, using everyday ingredients and a reliable method that produces consistent results every time. It works well for a midweek family supper or a relaxed weekend dinner with friends. From start to finish, it is ready in around 1 hour 15 minutes.

Ingredients

For the filling

450g skinless, boneless white fish fillets (such as cod or haddock), cut into large chunks
150g undyed smoked haddock, cut into chunks
200g raw king prawns, peeled
2 medium leeks, trimmed, washed, and sliced into 1cm rounds
30g unsalted butter
1 small onion, finely chopped
2 tablespoons plain flour
350ml whole milk
100ml fish stock
2 tablespoons double cream
1 tablespoon flat-leaf parsley, finely chopped
1 teaspoon Dijon mustard
Salt and freshly ground black pepper

For the mashed potato topping

800g floury potatoes (such as Maris Piper), peeled and cut into chunks
50g unsalted butter
60ml whole milk, warmed
Salt and white pepper
30g mature cheddar, finely grated (optional, for the topping)

How to Make Mary Berry Fish Pie With Leeks

Preheat the oven: Heat the oven to 200°C (180°C fan, gas mark 6). Lightly butter a medium ovenproof dish, roughly 25cm x 20cm in size.
Cook the potatoes: Place the potato chunks into a large saucepan of cold salted water and bring to the boil. Cook for 15 to 18 minutes until completely tender when pierced with a knife, then drain thoroughly. This is important because any excess water left in the potatoes will make the mash too loose to hold its shape on top of the pie.
Mash and season the topping: Return the drained potatoes to the pan and mash until smooth. Beat in the butter and warmed milk until the mash is creamy and lump-free. Season well with salt and white pepper, then set aside.
Soften the leeks: In a large, wide saucepan, melt the butter over a medium-low heat. Add the onion and cook gently for 3 minutes, then add the sliced leeks. Continue cooking for a further 5 to 6 minutes, stirring occasionally, until the leeks are soft and just beginning to turn translucent at the edges. Do not let them brown.
Build the sauce: Sprinkle the flour over the softened leeks and onion, stir well to coat evenly, and cook for 1 minute. Gradually pour in the milk and fish stock, a little at a time, stirring continuously to prevent lumps forming. Bring gently to the boil, then reduce the heat and simmer for 3 minutes until the sauce thickens and becomes glossy. Stir in the double cream, Dijon mustard, and chopped parsley, then remove from the heat.
Add the fish and prawns: Gently fold the raw fish pieces and prawns into the sauce, taking care not to break them up too much. The fish will cook fully in the oven, so there is no need to pre-cook it at this stage. Season with salt and black pepper, then pour the filling into the prepared ovenproof dish.
Top the pie: Spoon the mashed potato over the filling in generous dollops, then spread it carefully to cover the surface fully, reaching all the way to the edges to seal in the filling. Use a fork to rough up the surface into ridges, which will catch and turn golden in the oven. Scatter over the grated cheddar if using.
Bake the pie: Place the dish on the middle shelf of the oven and bake for 25 to 30 minutes, until the top is golden and lightly crisp, and the filling is bubbling up around the edges of the dish.
Rest before serving: Leave the pie to stand for 5 minutes before bringing it to the table. This allows the filling to settle slightly, making it much easier to portion cleanly.

Tips for the Best Mary Berry Fish Pie With Leeks

Why is my fish pie filling watery after baking?

This usually happens when the sauce is too thin before the fish is added. Make sure the sauce has thickened properly on the hob and coats the back of a spoon before folding in the fish. Some fish also releases liquid during cooking, so avoid using fish that has been frozen and not fully patted dry.

Why does my mashed potato topping sink into the filling?

The mash needs to be stiff enough to sit on top of a liquid filling. If it is too soft, it will absorb into the sauce as it bakes. Beat in only as much warmed milk as needed to make it smooth, and allow it to cool slightly before spreading it over the hot filling.

How do I stop the top of the fish pie from going pale and stodgy instead of golden?

Make sure the oven is fully preheated before the pie goes in. Roughing up the surface of the mash with a fork creates ridges that catch the heat, and these are what turn golden and lightly crisp. Adding a thin layer of grated cheddar also helps achieve colour and flavour on the surface.

Why are the leeks still a bit tough in the finished pie?

Leeks need enough time to soften fully on the hob before the sauce is built. If they go into the oven still firm, they will not have enough time to become tender during baking. Cook them gently until the edges are clearly soft and translucent before adding the flour.

Why does my sauce have lumps in it?

Lumps form when liquid is added too quickly to the flour and fat mixture. Add the milk and stock gradually, stirring constantly, and keep the heat on medium rather than high. If lumps do appear, use a whisk instead of a wooden spoon to work them out.

Serving Suggestions

Serve straight from the ovenproof dish with steamed tenderstem broccoli or fine green beans alongside for a simple, balanced plate.
Spoon onto warmed plates with a wedge of lemon on the side, the juice brightening the richness of the cream sauce.
Pair with a simple dressed green salad of watercress and cucumber for a lighter feel.
Serve with crusty white bread to scoop up any extra sauce left in the dish.
Offer a small jug of extra warmed cream at the table for those who like a richer finish.

Storage

Room Temperature

Fish pie should not be left at room temperature for more than 2 hours after cooking. Store any leftovers promptly.

Refrigerator

Allow the pie to cool completely, then cover the dish tightly with cling film or transfer portions to an airtight container. It will keep in the fridge for up to 2 days. Reheat individual portions in the oven at 180°C (160°C fan) for 20 to 25 minutes, or until piping hot throughout, before serving.

Freezing

The pie can be frozen before or after baking. If freezing before baking, assemble the pie fully, wrap the dish tightly in two layers of cling film followed by a layer of foil, and freeze for up to 2 months. Defrost overnight in the fridge, then bake as directed, adding an extra 5 to 10 minutes to ensure it is heated through to the centre.

Nutrition

Calories: 480 kcal
Carbohydrates: 38g
Protein: 34g
Fat: 20g
Saturated Fat: 11g
Sodium: 620mg

Nutrition values are estimates and may vary depending on the specific ingredients used and serving size.

FAQs

Can I use frozen fish in this recipe?

Yes, but thaw the fish completely in the fridge overnight and pat it dry thoroughly with kitchen paper before using it. Excess water from frozen fish will thin the sauce during baking, so drying it well is an important step.

Can I make this fish pie ahead of time?

The pie can be fully assembled up to a day in advance and kept covered in the fridge until ready to bake. Take it out of the fridge 20 minutes before baking to take the chill off, then bake as directed, adding 5 minutes to the baking time if needed.

Can I swap the leeks for a different vegetable?

Leeks give the pie its mild, slightly sweet flavour that works well with fish, but sliced fennel or finely diced celery can be used instead. Soften them in the same way before building the sauce.

Can I use cream cheese or crème fraîche instead of double cream?

Full-fat crème fraîche works well and gives a slightly tangy finish to the sauce. Stir it in at the same point as the double cream, off the heat, to prevent it from splitting. Avoid low-fat versions as they tend to separate during baking.

What size dish works best for this recipe?

A dish measuring roughly 25cm x 20cm and at least 6cm deep gives enough room for a generous filling layer and a good depth of mash on top. If the dish is too shallow, the filling may bubble over the sides during baking.

Conclusion

This Mary Berry fish pie with leeks brings together tender chunks of white fish and prawns in a creamy, well-seasoned sauce, all covered with a golden mashed potato topping that is crisp at the ridges and soft beneath. The leeks add a gentle sweetness that lifts the richness of the filling, and the whole dish comes together from a handful of straightforward ingredients using a reliable, easy method. This recipe serves 4 people generously.

Whether it is a Tuesday evening dinner or something to bring to a relaxed gathering, this pie holds its own on any table. If this recipe worked well for you, leave a comment below to share how it turned out, or pass it on to someone who would enjoy it. If you enjoyed this, you might also like the Mary Berry birthday cake recipe for your next celebration bake.