1.Preheat oven to moderate (180ºC/160ºC fan-forced). Grease 8cm x 25cm bar cake pan; line base and sides with baking paper, extending paper 2cm above long sides of pan.
2.Beat egg whites in small bowl with electric mixer until soft peaks form. Gradually add sugar, beating after each addition until sugar dissolves; fold in cardamom, rind, flour and nuts. Spread bread mixture into prepared pan.
3.Bake in moderate oven about 30 minutes or until browned lightly; cool in pan. Wrap in foil; stand overnight.
4.Preheat oven to slow (140ºC/120ºC fan-forced).
5.Using a serrated knife, cut bread into 3mm diagonal slices. Place slices on ungreased oven trays. Bake in slow oven about 15 minutes or until dry and crisp; turn onto wire rack to cool.
Uncut bread can be frozen after the first baking. After the second baking, bread slices can be kept up to one week if stored in an airtight container.Note