Cream the egg yolks and sugar together in a mixer until smooth thick and pale. Transfer to a large stainless steel bowl. Pour the cream into a small saucepan and bring to the boil over medium heat.
Gradually pour the hot cream over the egg mixture, beating continually. Place the bowl over a pot of simmering water (making sure the base of the bowl does not touch the water). And stir with a wooden spoon until the mixture thickens like a custard. Allow the mixture to cool, strew over chopped nuts and pour it into a serving bowl, cover with cling film and freeze overnight.