IN THE KITCHEN:
Beat together the butter, both the sugars and vanilla bean paste.
Mix in the egg then sift in the flour, cocoa powder and bicarbonate of soda. Stir well to combine then mix in the chocolate chunks.
Roll into walnut size balls and sit in the fridge (or freezer) until needed.
ON THE BARBEQUE:
Prepare the barbeque with the baffle in upright position and heat to approximately 180°C for baking.
Sit the cookies on a heavy based baking tray, that sits in the barbeque with the lid down, lined with baking paper or silicone. Place in the barbeque and cook with the lid down for 12 minutes (or 15 minutes of cooking from frozen).
Leave on the tray to cool for 5 minutes before tucking in to warm freshly baked cookies.