Step 1

Melt the butter in a saucepan.

Step 2

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

Step 3

Gradually stir in the milk, stirring constantly. Ensure that the milk is completely absorbed and the sauce is smooth and shiny before each addition of more milk. This will help ensure you get a smooth sauce with no lumps. Once all the milk is added, keep stirring, and bring the sauce to a gentle boil.

Step 4

Reduce the heat and simmer gently for 5 minutes. Season with salt and pepper.

Step 5

Stir in cheese and allow to melt. Don't re-boil the sauce or it will become stringy.