1.Preheat oven to 160°C. Grease 30cm square piece of foil.
2.Beat egg whites in small bowl with electric mixer until soft peaks form. Gradually add sugar, beating until dissolved between additions. Transfer mixture to medium bowl.
3.Fold in sifted dry ingredients and nuts; spoon mixture onto foil, shape into 7cm x 25cm log. Enclose firmly in foil; place on oven tray.
4.Bake about 45 minutes or until firm. Turn log out of foil onto wire rack to cool.
5.Preheat oven to 120°C.
6.Using serrated knife, slice log thinly. Place slices close together in single layer on oven trays. Bake about 20 minutes or until crisp; transfer to wire racks to cool.