Gratin of tagliatelle with sole

Main course: serves 6. Total time: 1 hour

This has the old-world charm of macaroni cheese, with the unlikely provenance of being on the menu at the beautiful Relais de la Magdelaine just behind Marseilles.

700g sole fillets, skinned
125ml white wine
sea salt, black pepper
25g unsalted butter
225g brown mushrooms, sliced
275g dried tagliatelle
150g Gruyère, grated Sauce
40g unsalted butter
25g plain flour
200ml double cream

Slice either side of the bony line that runs down the centre of the fillet, then cut the remaining strips across into 2cm pieces. Place the wine in a small saucepan with 225ml water and some seasoning. Bring it to a simmer, add the fish and submerge it using a wooden spoon. Bring back to a simmer, cover the pan and poach over a low heat for one minute. Strain off and reserve the liquid, and put the fish in the pan to one side.

To make the sauce, melt the 40g butter in a small saucepan, stir in the flour and cook the roux for one minute until it turns floury in appearance. Very gradually beat the reserved cooking liquor into the roux, then gradually add the cream. Bring the sauce to a simmer and leave it on a gentle heat for four minutes stirring occasionally, then taste for seasoning. At the same time melt the remaining 25g of butter in a large frying pan and sautée the mushrooms until soft and lightly coloured, seasoning them. Stir them into the sauce and leave it to cool while you cook the pasta.

Bring a large pan of salted water to the boil. Add the tagliatelle, give it a stir and cook until it is almost tender, but still on the chalky side. Drain it into a colander and refresh under the cold tap. Return it to the pan and toss with the sauce. Very gently fold in the reserved fish, transfer to a 35cm gratin dish and scatter over the Gruyère. Cover and chill until required. To serve, heat the oven to 200C fan oven/220C or 425F electric oven/Gas 7 and cook it for 20-25 minutes until golden and bubbling.