Tear sponge cake into large chunks. Line the bottom of a loaf tin with sponge pieces, reserving some pieces to cover the top.

Heat lemon juice, lemon rind, water, and sugar in a saucepan.

Separately, beat 2 egg yolks. Add to the saucepan - do not boil.

Mix gelatine with 1/4 cup of cold water and stir into saucepan. Cool.

Beat 2 egg whites to soft peaks, and separately whip cream or evaporated milk. Mix both into the cooled saucepan.

Pour half the mixture over the sponge cake and cover with remaining sponge pieces. Pour over the remaining half of the mixture.

Refrigerate 24 hours.

Turn out and decorate with whipped cream and nuts to serve.