How to make
On a heated hob, in a suitable saucepan, melt the flour with the butter and stir it for another minute or so, just so that the flour does not remain in its raw form.
Add the boiling milk to the mixture, pouring it in gradually, but stir vigorously.
Boil it for 10 minutes or more, if you want it to be thicker. Add salt and grate the nutmeg.