Blend the hazelnuts and the icing sugar together and sieve twice. This is to avoid any lumps in the batter later. Set aside.

Place the caster sugar and the egg whites in a bowl and start whisking on a bain-marie without the boiling water touching the bowl. Once the sugar is completely dissolved, remove the bowl from the stove and continue to whisk to medium stiff peaks.

Add the food colouring at this stage and start adding the sugar blend little at the time. Fold the mixture creating either a ‘J’ or by the ‘spin’ method. This will ensure that little air is incorporated in the mixture.

Pre-heat the over at 140 c and pour the mixture in a piping bag. Pipe the shells onto parchment paper and let rest until dried. This will take approximately 30 minutes. If you feel that there may be air in the mixture, make sure to crush the tray on the kitchen side to knock any air out.

Bake until dried and you can see the little feet coming through. The result should be a gooey centre with a crunchy layer.