You asked for it – so here it is the recipe for the biscotti.
400ml egg whites
560g plain flour
*so here you can substitute, eg. 200g pistaschio and 200g cranberries, or 400g almonds, dried figs, choc chips etc, etc but it should be a total of 400g
Whisk egg whites and sugar until you can feel that the sugar has dissolved and you have a glossy white meringue like mixture. Add in sifted flour and nuts. With this quantity pour half the mixture on lined baking tray and pour the other half on another lined baking tray [they will look like flat rustic loaves]. Cook for 50-55 minutes at 150 degrees. Whilst still warm slice thin with a serrated bread knife the biscotti, the thinner the better I think but you can cut them a little thicker for ease. Place back on lined tray and back into the oven for 10 minutes. After 10 minutes, turn the biscotti over and bake for another 10 minutes. These last 20 minutes are vital to give the biscotti the crisp crunchy texture. Put the kettle on and enjoy.