In a dry heavy sauce pan, dry roast the flour till light pinkish in colour.
Remove and keep aside to cool.
Melt butter in the pan, add half the milk.
Mix the remaining milk in the cooled flour to form a smooth paste.
When milk comes to a boil, add paste and stir continuously.
Bring back to a boil.
Cook till the sauce is thick enough to coat the back of a spoon thickly.
Sprinkle salt and fresh ground pepper and stir to mix well.
Add grated cheese to the mixture.
Use as required in individual recipes.