Slowly bring the milk to the boil with the bay leaf and the onion. Slowly, because we wish to infuse the milk with the bay and onion flavours.
Melt the butter in another pan (it must be big enough to comfortably hold the milk), then add the flour. Stir in to make a roux by cooking over a medium heat, stirring continuously with a wooden spoon for 10 minutes. Slowly start to add the strained milk. Stir well to avoid lumps. When all the milk has been added, and has been absorbed by the flour, cook for 20 minutes until thick and creamy. Season to taste with salt, pepper and nutmeg, and use immediately. If not using immediately, pour into a bowl and press a sheet of clingfilm on to the surface of the sauce before it forms a skin. Allow to cool and refrigerate.
© 1996 Alastair Little. All rights reserved.