Simple cheese sauce

1) Place butter, milk and flour in a saucepan over a medium heat and whisk until starting to thicken.
2) Turn down the heat and add the cheese, stir until melted.
3) Check the seasoning and serve as needed.

Note: if you are using your sauce to pour over vegetables, fish etc. and will then be putting it in the oven, add half of the cheese at step 2 and sprinkle the other half over before baking.