- Preheat the oven to 180ºC (160ºC fan oven). Put the potatoes in a pan of salted water, bring to the boil, cover and simmer for 20min. Add the eggs to the pan and cook for 8min until hard-boiled and potatoes are almost tender. Remove the eggs and put in a bowl of icy cold water. Warm 200ml of the milk.
- Drain the potatoes, return to the pan and cook over a low heat for 2min. Mash potatoes until smooth. Stir in 150g butter, half the cheese and the warmed milk and season to taste with salt and freshly ground black pepper. Beat together well, cover and put to one side.
- Meanwhile, divide the wine, stock and remaining milk between two large wide pans and bring to the boil. Add the haddock and salmon, return the liquid to the boil, then turn down the heat to poach the fish gently for 5min or until just beginning to flake. Using a draining spoon, lift the fish into two 1.4 litre capacity deep ovenproof dishes and flake with a fork if necessary. Reserve cooking liquid.
- Melt the remaining 75g butter in another pan, add the flour, stir until smooth and cook for 2min. Gradually add the fish liquid, whisking until smooth. Bring to the boil, stirring, and cook for 2min or until thickened. Stir in the cream, capers and parsley, season to taste.
- Peel the eggs, chop roughly, scatter over the fish, then ladle sauce evenly over the top. Spoon potato mixture over the sauce and sprinkle with the remaining cheese. Bake for 35-40min until golden and hot.
To freeze: Cool sauce before pouring over fish and eggs. Freeze at the end of step 5 for up to three months.
To serve: Thaw overnight at cool room temperature. Bake at 190ºC (170ºC fan oven) for 50-60min or until golden and bubbling at the edges.
A brilliant dish to prepare ahead, ready to pop in the oven when needed.
Recipe via thefishsite.com