Note: this makes about half a litre.
Note: consider making macaroons or
tuile or meringue with the left-over
Note: benefits from using a food mixer.
450 ml milk
120 gm sugar
4 egg yolks
60 gm flour
Whisk together the eggs and the sugar: it is an advantage
if you can do this in a food mixer for reasons that become
Mix in the flour to form a smooth paste (in the food mixer
if you're doing that).
Bring the milk to the boil in a pan.
Allow the milk to cool for 10 minutes (so that the egg
doesn't turn into scrambled) and then gradually add
the milk to the bowl with the egg yolks and sugar in it,
mixing and stirring well; if you are using a food mixer you
can do this by running the mixer while slowly pouring in the
milk: it may be a good idea to pause and scrape the
sides/bottom of the mixer bowl half way to ensure no lumps.
Wash out the pan to remove the stuck-on milk residue,
return the mixture to it and bring to the boil, stirring continuously,
until the mixture thickens; it will thicken really
suddenly, make sure to be stirring vigorously at this point to
avoid lumps forming.
Pour into a bowl, cover with cling film and allow to cool;
if the cling film can touch the surface of the custard that
will avoid a skin forming.