Step 1

Melt the butter in a saucepan.

Step 2

Stir in the flour and cook for 1-2 minutes.

Step 3

Take the pan off the heat and gradually stir in one-third of the milk. Return to the heat and simmer, stirring, until all the milk is absorbed.

Step 4

Repeat this process, stirring all the time, allowing the sauce to become thick and shiny before adding more milk.

Step 5

When all the milk is added bring to the boil. Simmer gently for 8-10 minutes and season with salt and white pepper.