champagne sauce

50g butter
60g shallots, very finely sliced
60g button mushrooms, finely sliced
400ml brut champagne or sparkling wine
300ml fish stock
500ml double cream
salt and freshly ground white pepper

In a saucepan, melt 20g butter. Add the chopped shallots and sweat them for I minute. Add the mushrooms and cook for a further 2 minutes, stirring continuously with a wooden spatula

Pour in the Champagne and reduce by one-third over medium heat. Add the fish stock and reduce the sauce by half

Pour in the cream and reduce the sauce until it lightly coats the back of a spoon. Pass it through a fine sieve into a clean pan.

Whisk in the remaining butter, a little at a time, then season the sauce with salt and pepper


for poached white fish, such as John Dory, turbot or sole