Lodge a basin over a saucepan of hot water.
Put in egg yolks and sugar and whisk until the mixture is creamy in colour and consistency.
Add the wine gradually and stir slowly.
The mixture should be firm enough to take the impression of the back of a spoon.
Be careful not to over cook it or it may curdle.
Spoon the mixture into individual glasses and serve at once with Boudoir biscuits or wafer biscuits.