No roux white sauce (v)

[mike]

White sauce
1 pint milk
4 tbsp plain flour
1/2 oz butter (1/4" off a block)
1 mozzarella ball
1 tsp english mustard

Put the milk and flour into a saucepan. Whisk until the lumps have disappeared. Add the butter and put on a medium heat.

Keep whisking until the sauce comes to a simmer, and turn down the heat.

Add the mozzarella and keep whisking until melted.

Add the mustard.