Basic Cheese Sauce

• 900 ml (1½ pints, 3¾ cups) milk
• 1

Put the milk and onion in a pan and bring to the boil, then remove from the heat and leave to stand for 5 minutes. Melt the butter in a separate pan and stir in the flour to make a roux. Cook gently, stirring, for 2-3 minutes.

Remove the onion from the milk and add the milk to the roux a little at a time, stirring constantly. Bring slowly to the boil, then reduce the heat