This version of sabayon, the light egg custard is a very old recipe from Eliza Acton, mysteriously called ‘German sauce’.
Warm the sherry gently until hot, taking care not to let it boil.
In a bowl, whisk the egg yolks with the sugar until pale. Add the lemon juice, then whisk in the hot liquor, pouring it in slowly.
Return this mixture to the pan and continue to whisk over a low heat until the custard thickens. (You may prefer to do this in a double saucepan or in a bowl set over boiling water.) The custard will be light and frothy. Serve with langues-de-chat or other biscuits.
© 1998 Alastair Little and Richard Whittington estate. All rights reserved.