Required: Two hard-boiled yolks of eggs. One teaspoonful of castor sugar. One teaspoonful of dry mustard.

Quarter of a teaspoonful each of salt and pepper. Quarter of a pint of cream. One tablespoonful of vinegar.

Rub the yolks through a sieve, add to them the sugar, mustard, salt and pepper. Mix all well together, then add the cream very slowly, stirring it all the time. Lastly, add the vinegar, and it is ready for use.