Swap out salmon for our sustainable fish pie

Photographer: Maria Kovaleva

Published: 15 Jul 2020

Christina O'Sullivan shares the shocking truth about salmon and introduces us to a more sustainable fish pie.

Had salmon for supper recently? If so, you are not alone, a recent survey showed that salmon is the UK's most popular fish dish. Salmon is good for us, but our love of it puts pressure on our oceans. 

The salmon on your dinner plate is probably farmed, around 60% of the world’s salmon production is farmed, and in Scotland this figure reaches 100%, with the last commercial wild salmon fishery closing in late 2018. Farming salmon at an industrial scale requires large quantities of feed including wild caught fish. The current quantity of wild fish fed to farmed Scottish salmon, 460,000 tonnes, is roughly equivalent to the amount of fish purchased by the entire UK population. 

Even worse, research shows that 90% of wild caught fish used to produce feed are edible – what if we ate that fish instead of feeding it to salmon? This pie uses fish that are often fed to farmed salmon. We’re are asking you to swap salmon for something a bit different – turns out there is plenty more (interesting) fish in the sea. For more fish swaps, read our article: Top of the Swaps! 

Check out Sustain's Fish Cities campaign

Sustainable Fish Pie

Keenan Humble, from Alchemic Kitchen, give us a sustainble fish pie recipe. Using often overlooked fish to create a tasty and sustainable supper. It is designed to be flexible so feel free to use different fish and ask your fishmonger for any top tips.   


For the topping  

1.5kg potatoes (peeled and chopped) 

75g butter  

Dash of milk  

50g finely grated hard cheese 

For the filling 

1 large onion (diced) 

1 leek (diced) 

750ml milk 

1 bay leaf  

200g frozen peas 

600g fillets of kippers or herring, depending on whether you want a smoked flavour or not 

800g whiting fillets (deboned and cut into 2cm cubes) 

75g butter, plus a little extra for frying  

75g all-purpose flour 

½ bunch parsley (chopped) 

Salt & pepper  

3 eggs (hard boiled & sliced) 



Boil the potatoes until cooked. Drain, then leave to steam in a cullender. Mash the potato while still warm with the butter and a dash of milk, set aside.  

For the filling, put a knob of butter into a saucepan, add the onion and leek and cook until softened. Pour over the milk, add the bay leaf, salt and pepper and frozen peas and bring to a simmer.  When simmering, add the kipper fillets and cook until the fish starts to flake. Remove the kippers, allow to cool slightly, before picking the meat away from the skin and discarding any bones. Add the whiting into the milk, and cook until they are not quite flaking, the fish will continue cooking in the oven.  

Strain the milk mixture through a sieve (saving the milk in a jug or bowl), remove the bay leaf and put the whiting, onion and leek into an over proof dish with the kippers.  

In the saucepan that you cooked the fish, melt the butter over a medium heat, before pouring in the flour. Stir this constantly to make a smooth paste in the pan, you do not want to colour the paste, but you need to cook the flour for a minute or so. Gradually add the infused milk, whisking to ensure the sauce remains smooth. Add the parsley to the sauce and pour over the fish. Place the eggs in a layer over the fish before topping with potato. Spread evenly and run a fork over the top of the surface. Sprinkle with grated cheese.  

Bake in the oven for 40 minutes at 200C/180C Fan/Gas Mark 6 until the top is golden and crisp.  

Want to know more about UK fish? Check out Feedback's Fishy Business campaign.

@feedbackorg @alchemic_kitchen

 Still hungry? Here's another sustainable recipe - Broad Bean Guacamole.