Cut the potatoes into quarters and steam until soft

Mash using a ricer and add 25g of the butter

Place onto a low temperature and mix the butter in using a spatula

Season to taste and set aside to cool

Place the fish stock into a saucepan

Place over a medium temperature and bring to a simmer

Blanch the spinach and remove

Set aside in a colander to drain

Simmer the carrots until nearly soft and then remove and set aside

Lightly poach the fish, in batches

Remove using a slotted spoon and set aside to cool before flaking

Pour the poaching liquid into a measuring jug

Top up to 500mls with boiling water

Place the saucepan back onto the heat

Add 40g of the butter and allow to melt

Make a roux with the flour and cook out for one minute

Add the stock slowly until you have a nice thick sauce

Reduce the heat and leave to simmer for 5 minutes

Preheat the oven to 180° Celsius

Press the excess liquid out of the spinach

Place it on the bottom of an oven proof dish

Season to taste (do this for each layer)

Add the carrots

Top with the flaked fish - for a pretty effect, do each fish in its own layer

Top with the mashed potatoes

I piped mine on, but you don't need to

Sprinkle the top with paprika

Bake for 30 minutes and allow to cool for 5 minutes before serving