Pre-heat the oven to 180°C and line 2 large baking trays with non-stick baking paper.
Beat the butter in a mixing bowl until creamy then add the honey and salt and mix to combine.
Add the flours with the guar gum and work with your hands into a dough.
Shape the dough into a ball and then flatten into a disc.
Roll out the dough between 2 sheets of non-stick baking paper to 1cm thickness.
Cut the dough into rectangles or in favourite shapes with the help of biscuits moulds.
Place apart on the baking tray and prick with a fork; sprinkle with brown sugar.
Bake for 14-15 minutes, until golden.
Cool the shortbread biscuits on the baking trays for a few minutes, then place on a wire rack to cool completely.