Beat the butte with the vanilla and Natvia until creamy. Add the flour and cornflour. Beat on low until combined.
Lightly dust the bench top and then quickly bring the dough together by lightly kneading. Lightly flour a rolling pin and roll out.
Cut with a small cookie cutter and place each cookie on a baking paper lined oven tray.
Bake for 8 minutes. Remove from the oven and, working quickly brush the tops of the cookies with egg white an then place the leaves of the lemon thyme on top. Brush over the top with egg white. Bake for another 3-5 minutes.
Remove from the oven and stand on the tray for -3 minutes. Remove to a wire rack until cooled.
TIP: You can use any type of herb you like or even edible flowers.