Fish Pie with Leeks is a delicious combination and this recipe combines different types of fish in a lovely creamy white sauce, flavoured with lemon and topped with mashed potato. There's no waste and it's the perfect winter comfort food. This fish pie recipe doesn't contain cheese, eggs, or cream.

If you don't have any fresh fish, you can make this fish pie with frozen fish. Just add the frozen fish to the milk and cook. It will take a few minutes longer but is perfectly ok.
For a super quick and simple fish pie, my Cod Mornay is the most straightforward recipe you'll find and is ready in just 30 minutes.
Fish makes great comfort food and these other fish recipes are perfect in colder weather. Smoked Haddock and Prawn Chowder or a traditional Scottish dish also made with smoked haddock and leeks called Cullen Skink.
Jump to:
Ingredients
Everything you need for Fish Pie with Leeks.
- Fish - The beauty of a fish pie is you can use any fish. I like a combination of white fish, smoked fish, and prawns. You can substitute one of these for an oily fish such as salmon or trout. Or, just use one type of fish if you prefer. If possible, I recommend avoiding the pre-packaged fish pie mixes which can contain lower-quality fish.
- Potatoes - use a variety with a higher starch content that will mash easily such as Maris Piper, King Edward, or Desiree. In the US, go for Russets or Yukon Gold.
- Vegetables - Kale and peas make this a great one-pot meal and easily cook in the sauce.
- Milk - use any dairy milk, full fat, semi-skimmed, or skimmed.
See recipe card for quantities.
Instructions
Gather all your ingredients together and make sure your fish doesn't contain any bones. You don't need to remove the skin as that comes off easily once cooked.
Pre-heat the oven to 190°C/375°F/ or gas mark 5. Place a pan of lightly salted water on the hob to boil. Peel the potatoes and cut them into 3cm² chunks. This will speed up the cooking time. Place them in the pan and simmer for around 10 minutes until soft.
Place the kale in a steamer and steam over the top of the potatoes for the last 5 minutes.
Drain the potatoes and mash, add a little milk or butter to soften if you like then leave to one side. Meanwhile, heat the milk in a large pan and add the fish. Bring the milk to a boil then turn down the heat and simmer for 6 - 7 minutes.
Heat the butter in a large pan and gently fry the leeks for 4 - 5 minutes until soft, but not brown.
Remove the fish from the pan and set it aside to cool. Pour the milk into a jug.
Add the flour to the leeks and stir well. Over a low heat, gradually add all the milk, stirring all the time. Season with salt and freshly ground black pepper.
Carefully break the fish into chunks, leaving behind the skin, and stir into the sauce. Add the prawns, peas, kale, and lemon zest.
Transfer your fish pie filling to an oven-proof dish.
Cover with the mashed potatoes using a fork to spread evenly. Start at the edges of the dish and work in towards the middle.
Bake in the oven for 25 minutes.
Hint: As soon as you have poured the milk into a jug, rinse your milk pan in water as this makes it much easier to clean.
Substitutions
- Fish - You can use lots of different types of fish in a fish pie. Round white fish or those with a more meaty texture are better than flat fish varieties such as plaice and sole which will break up in the sauce. Coley, hake, basa, pollock bream or monkfish are good varieties of white fish to use.
- Vegetables - other vegetables you could use include cabbage, spinach, broccoli, or sweetcorn. Adding vegetables to the sauce makes this a great one-pot dish.
- Gluten Free - if you need to make the sauce gluten-free, substitute the plain or all-purpose flour with Cornflour. You will need to half the quantity as cornflour is a stronger thickening agent than plain flour.
Serving suggestion
There is no need to serve extra vegetables on the side as it's all added in. Vegetables that go well as side dishes include sweetcorn, carrots, and steamed green vegetables. A simple green salad adds some colour to the plate. My kids always insist on ketchup!
Equipment
You will need one oven-proof casserole dish, one pan for poaching the fish, and another large pan to mix all the ingredients for the fish pie filling.
Sustainability
When buying fish look for the Marine Stewardship Council label. This is a good indication the fish has been sustainably sourced. Buying sustainably sourced fish is important to protect the long term stocks of different varieties of fish and also to protect the marine environment.
Storage & Freezing
Fish pie with leeks will keep in the fridge for 2-3 days. You can also assemble it, keep it in the fridge and cook it up to 48 hours later.
It can be frozen for around 3 months. After 3 months it will still be safe to eat, but the texture may change slightly. If you are planning on freezing the fish pie, it is best frozen once assembled but before being cooked in the oven. Let it cool then cover it and place it in the freezer. If your fish pie has not already been cooked, leave it uncovered when reheating it so the top goes golden brown and crisp.
How to reheat Fish Pie
Cover the top with foil to prevent the top from browning any further. Reheat in the oven at 180C/350 F/gas mark 4 for about 40 minutes until piping hot. To check if it is piping hot in the middle, insert a fork, leave for a few seconds and then test on the back of your wrist to check if the fork is hot. It is best to defrost the pie first before reheating it. If reheating from frozen, this will take around 1 ½ hours. Cover the fish pie for half the reheating time to stop the potato from going too brown or burning.
Top tip
To make sure your mash doesn't sink into the filling, let your cooked potatoes steam for a few minutes. This helps dry them out a little. Watery potatoes will weigh heavy and will seep into the filling.
Related
Looking for other recipes like this? Try these:
📖 Recipe
Fish Pie with Leeks
Ingredients
- 1 kg potatoes organic
- 80 g kale organic, or spinach or cabbage, shredded
- 750 ml milk organic
- 250 g smoked haddock MCS certified
- 200 g white fish fillets MCS certified
- 50 g butter organic
- 360 g leeks organic, washed and sliced
- 3 tablespoon plain flour organic
- 100 g prawns cooked, peeled, defrosted MCS certified
- 100 g frozen peas organic
- 1 lemons organic, fairtrade, zest only
Instructions
- Pre-heat the oven to 190°C/375°F/gas mark 5. Place a pan of lightly salted water on the hob to boil. Peel the potatoes and cut them into 3cm² chunks. Place them in the pan and simmer for around 10 minutes until soft.1 kg potatoes
- Place the kale in a steamer and steam over the top of the potatoes for the last 5 minutes.80 g kale
- Drain the potatoes and mash, add a little milk or butter to soften if you like then leave to one side. Meanwhile, heat the milk in a large pan and add the fish. Bring the milk to a boil then turn down the heat and simmer for 6 - 7 minutes.750 ml milk, 250 g smoked haddock, 200 g white fish fillets
- Heat the butter in a large pan and gently fry the leeks for 4 - 5 minutes until soft, but not brown.50 g butter, 360 g leeks
- Remove the fish from the pan and set it aside to cool. Pour the milk into a jug. Top tip. Put your milk pan into a bowl of hot water immediately, or it can be a pain to clean.
- Add the flour to the leeks and stir well. Over a low heat, gradually add all the milk, stirring all the time. Season with salt and freshly ground black pepper.3 tablespoon plain flour
- Carefully break the fish into chunks, leaving behind the skin, and stir into the sauce. Add the prawns, peas, kale, and lemon zest.100 g prawns, 100 g frozen peas, 1 lemons
- Place it all in an ovenproof dish, and cover it with the mashed potatoes using a fork to spread it evenly. Start at the edges of the dish and work in towards the middle. Bake in the oven for 25 minutes.
Notes
Tips
- You can use any fish in a fish pie. Try a combination of white fish and smoked or oily fish. You could also just use one type if you prefer. A fish pie mix is convenient, but buying the fish separately is usually better value.
- Other vegetables you could use include cabbage, spinach, broccoli, and sweetcorn.
- The best potatoes to use for mash are Desiree or Maris Piper potatoes in the UK and Russets or Yukon Gold in the US. These are higher starch potatoes and will give a light fluffy mash. Waxy potatoes are more difficult to mash and you can end up with a potato paste rather than a fluffy mash. You could also try using sweet potatoes instead or half and half.
- To make sure your mash doesn't sink into the filling, let your cooked potatoes steam for a few minutes. This helps dry them out a little. Watery potatoes weigh heavily and will seep into the filling. When adding the mashed potatoes, use a dessert or tablespoon and spoon it on one spoonful at a time. Start at the edges and work inwards towards the middle. Once you've covered the filling, you can go over the top with a fork to make a pattern or little grooves in the potato that will crisp up nicely in the oven.
Storing and Reheating
- To reheat fish pie, cover with foil and reheat in the oven at 180C/350F/Gas Mark 4 for around 40 minutes until piping hot. To reheat from frozen allow around 1 ½ hours.
- Fish pie can be frozen for up to 3 months. It can be frozen once assembled, without being cooked in the oven. If your fish pie has not already been cooked, leave it uncovered when reheating to allow it to brown on the top.
- It can be stored cooked in the fridge for 2 - 3 days. You can also assemble it up to 48 hours in advance and keep it in the fridge.
Nutrition per serving
The Nutritional Values are computer generated estimates based on industry standards and are provided as a helpful guide only.
Bren
Delicious. Tasty and hearty meal.
Easy peasy recipe. Can't go wrong !
Thanks, Claire
Stephanie
That looks delicious! I grew up in a house where seafood was banned due to an allergy, so now I like to try it in as many dishes as I can!
kushigalu
Love the combination of flavours in this recipe. So delicious. Thanks for sharing
Sandra
A delicious satisfying comfort food and we love the lemon flavour in combination with the creamy white sauce. Thanks for the recipe!!
Beth
This looks really good. I've had fish in a lot of ways, but I've never had fish pie. I love the ingredients, and I can't wait to make it.
Paul
Tasty, colourful and impossible to get wrong! Love this recipe!