50g butter, melted One side of salmon skin on and boned 1 small bunch tarragon, roughly chopped 120ml dry white wine Juice of half a lemon Salt and freshly ground black pepper For the beurre blanc: 50g shallots very finely chopped 2 tbsp white wine vinegar 4 tbsp dry white wine 6 tbsp water or Fish stock 2 tbsp double cream 175g unsalted butter, cut into small pieces Salt and freshly ground white pepper
To make the beurre blanc, put the shallots, vinegar, wine and water or stock into a small pan and simmer until nearly all the liquid has evaporated. Add the cream and boil until reduced a little more. Lower the heat and gradually whisk in the butter, a few pieces at a time, until amalgamated. Season to taste. Preheat oven to 220°. Brush the centre of a large sheet of foil with some of the melted butter. Place the salmon fillet skin side down in the centre and bring the edges of the foil up around the fish slightly. Put the open parcel on to a large baking tray.
Mix the tarragon with the rest of the melted butter, plus the wine, lemon juice, salt and pepper. Spoon the mixture onto the fish and close the foil to make a loose airtight parcel. Bake for 20–25 minutes. Remove the fish from the oven, place on a warmed serving dish and serve with the beurre blanc and vegetable and green salad.