Boulangère potatoes
Indulge yourself and shake off those winter blues with our best Boulangère potatoes, a lighter, dairy free alternative to Dauphinoise. Ideal as a side to roast lamb or chicken, or use vegetable stock to make it veggie-friendly
Dissolve 1 tbsp of salt in 100ml of just-boiled water, leave to cool then refrigerate until cold. Submerge the fish in the brine in a small dish, and leave in the fridge for 1 hr. Rinse the fillets under cold water and pat dry with kitchen paper. Refrigerate until needed.
Meanwhile, put a large pan over a medium heat and add 1 tbsp of oil. Once hot, fry the onion, garlic and celery for 3-4 mins until softened. Add the fish carcass and cook for a further 5 mins. Add the brandy and flame carefully with a kitchen blowtorch or long match. Gently shake the pan until the flames die down, then add the tomato juice, purée, parsley and thyme with 150ml of water. Bring to a gentle boil, then reduce the heat and simmer for 1 hr. Remove the thyme, carcass and all the bone and fish you can. Transfer to a blender and blitz until smooth. Pour the sauce through a sieve and set aside in a small pan.
Add the peas to the water and blanch for 2 mins. Drain and pulse in a food processor until chunky. Mix with the mint and half the butter in a bowl, season and set aside.
Add the remaining oil to a large, non-stick frying pan over a medium heat. Once hot, cook the fish, skin-side down, for 2-3 mins or until the skin starts to colour. Turn off the heat, add the remaining butter and gently shake the pan to distribute, turn the fish to finish cooking for another 2-3 mins. Gently reheat the sauce. Divide the peas between two plates and top with the fish. Drizzle with the sauce and serve.