The Jews of a Lsace were proud of the many delicate sweets in their repertoire. This one is a savoury-sweet classic, and a quintessential French Pastry.
Sift the flour, salt and nutmeg together in a large bowl. Make a well in the centre. Add the egg yolk and about half of the milk. Beat until smooth, then gradually beat in the remaining milk.
Whisk the egg white in a bowl until stiff. Fold into the batter.