Put the egg whites into a blender with salt and lemon juice.
Add 1 ounce of sugar to the egg whites while blending.
In a separate bowl, blend the flour, 5 ounces of sugar and ground hazelnuts.
Add beaten egg whites to bowl with hazelnut/sugar mixture and fold in with a spatula.
Butter the bottom of a baking sheet, cover with buttered parchment paper.
Pour biscuit dough on parchment and place in 475 F over for 5 minutes, rotating pan often.
When cooked, cool in the refrigerator.