Grate the rinds of 2 lemons and squeeze
the juice from all 3. Separate the eggs. Beat the egg yolks with the
grated rind, lemon juice and sugar and put them in to a saucepan.
Stand the saucepan in a bain-marie and stir until the mixture is thick
enough to coat the back of a spoon. Put aside to cool. Whisk the egg
whites until they form peaks, then fold them into the lemon cream.
Transfer to a serving bowl and leave in the refrigerator for several
hours until required. Serve very cold but not frozen.
