The quantities of flour and fat used to make this versatile sauce are varied to produce different consistencies for different uses. For 300ml (½pint) thin pouring sauce use 15g (½oz) each butter and plain flour; and for a thick binding sauce for making soufflés, 25g (1oz) each butter and flour.
Melt the butter in a heavy-based saucepan. Whisk in the flour until the roux is blended and sandy coloured. Cook for 2 minutes, whisking constantly. Remove the pan from the heat.
Gradually whisk in 300ml (½pint) milk. Return to the heat and whisk until the sauce thickens and boils, then simmer for 2–3 minutes, whisking occasionally. Season to taste.
For a quick version, use the classic quantities (above) and put the fat, flour, milk and seasoning into the pan in one go. Bring to the boil, stirring constantly with a wooden spoon, until thickened. Simmerfor 2 minutes, season well, then use as required.
To make a parsley sauce make a medium coating white sauce (above) and stir in a finely chopped large bunch of parsley. Simmer gently for 1–2 minutes, then season to taste. Serve with boiled meats, steamed chicken breasts, fish cooked in any way or with vegetables.