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