1) Add the nuts to a clean blender and blend them into a chunky mixture. Keep the nuts quite rough to add more crunch to your cookies.
2) Place the blended nuts aside until needed later. Pour the egg whites in a large mixing bowl. Beat them for 2 minutes until foamy and a little glossy. Then pour in the caster sugar.
3) Beat well again until the egg whites have thickened quite a lot but are not stiff yet. Then add the vanilla extract and the sesame oil.
4) Beat for another minute. Sprinkle the egg whites with the plain flour and add a tiny pinch of salt as well.
5) Beat the egg whites for another 3 minutes. Then pour in the blended nuts (keep a little aside for garnish if you like).
6) Stir the whites with a spoon now until you get a thick and sticky chunky batter. Line a baking tray with a sheet of baking paper. Using 2 teaspoons place little dollops of the egg white batter on top of it. Sprinkle with the remaining blended nuts if you kept some aside.
7) Then bake the cookies in a preheated oven at 325°F (160°C) for 25 to 30 minutes. Then remove the freshly baked cookies from the hot oven and place them on a wire rack to cool.