Ingredients
3 eggs (at room temperature)
50g butter, plus extra to serve
2 tbsp rapeseed oil, plus a drizzle
2 onions, chopped
50g plain flour
600ml milk
6 small cornichons (about 2 tbsp), rinsed and finely chopped
1 tbsp capers, rinsed and finely chopped
1 small bunch flat-leaf parsley
1 lemon, zested and juiced
800g floury potatoes, such as Maris Piper
600g skinless and boneless haddock or cod, cut into chunks
1 tbsp malt vinegar
200g frozen peas
Boil the eggs for 7 mins, then plunge straight into cold water and set aside to cool.
Melt the butter in a large saucepan and add the oil and onions. Cook for 5 mins or until soft. Stir in the flour for 1 min to make a paste, then add the milk bit by bit, stirring as you go, to make a smooth sauce the consistency of double cream. Add the parsley, cornichons, capers and lemon juice, and season to taste.
Heat oven to 200C/180C fan/gas 6. Peel the potatoes, cut into chips, put in a pan of water. Bring to a simmer, cook for 2 mins, then drain – the potatoes should still hold their shape. Leave to steamdry for 5 mins.
Spread half the sauce over the base of a large shallow casserole dish (ours was 30cm). Scatter the fish on top, peel and quarter the eggs, and add these too. Top with the remaining sauce.
In a bowl, toss the chips with the vinegar, a drizzle of oil and some seasoning. Scatter over the pie and bake for 40 mins until the potatoes are golden.
Meanwhile, cook the peas in a pan of boiling water for 2-3 mins, then drain and mash lightly with a knob of butter and the lemon zest. Serve alongside the pie.