Melt butter
and sugar and cook until caramel color.
At
this time stay close to it and wait until the forming of a foam on top of the caramel .
It looks like it is burning and is burning in fact.
At this time add the half & half
gradually
BE VERY CAREFULL
Add the remaining liquid and bring it back
to the boil
Then using
the mixture yolks / sugar proceed like the making of the crème Anglaise