Preheat the oven to 170°C/Fan 150°C/Gas 3. Line a couple of baking sheets with baking parchment.

Using a stand mixer, or electric hand whisk and bowl, whisk the egg whites and erythritol to stiff peaks. Fold in the ground flaxseed, ground almonds, baking powder and salt. Work until the dough is evenly combined and forms a ball.

Roll out the dough between two sheets of baking parchment to about a 5mm thickness. Remove the top sheet of parchment and cut out 7cm rounds from the dough. Gently re-roll any scraps and cut out more rounds.

Place the dough rounds on the prepared baking sheets and bake for 25–30 minutes.

Remove from the oven and leave the biscuits on the baking sheets for about 5 minutes to firm up, then transfer to a wire rack to cool.