Sift the flours
Whip the egg yolks and sugar until pale.
Fold in the rest of the ingredients for the egg yolk mixture.
Make the meringue by whipping the egg whites and lemon juice and sugar until stiff peak is formed.
Combine the two egg mixtures, mixing 1/3 of the meringue with the egg yolk mixture at a time.
Bake at 165C for 30 minutes, and 150C for another 15 minutes until done.
When it leaves the oven,give it a good bang against the bench from a height of 30cm, then leave it to cool upside down for at least 30 minutes.