How to cook
Bake the hazelnuts for 20 minutes in the oven on a low setting and crush them.
Mix the egg whites with the sugar, then add the nuts and lemon zest. Stir well and with a teaspoon pour them, with some spaces in between, in a tray covered with parchment paper.
Bake in the oven on low. Take them out and let them cool, and only then take them off the paper.