This is very good with poached chicken or cod. For the wine, something bone-dry, like an Orvieto Classico, would be suitably Italian.
First make a basic béchamel: melt the butter over a gentle heat. Stir in the flour and cook to a roux for 2 minutes. Pour in the milk and simmer, stirring occasionally, for 20–30 minutes, when it should be thick and creamy and reduced to about
Sweat the shallots until soft in the butter. Add the mushrooms and continue to fry gently for 5 minutes or so.
Pour over the wine, turn up the heat and bubble down quickly, until almost evaporated.
Stir in the béchamel, lemon juice, parsley and nutmeg to taste. Simmer for 3–4 minutes. Just before serving, stir in a few tablespoons of double cream if you like.
© 1998 Alastair Little and Richard Whittington estate. All rights reserved.