Preheat the oven to 350 and line a couple of baking pans with parchment – as I mentioned these are large cookies and I only placed 5 on each pan.

Whisk together the flour, salt and baking soda in a small bowl and set aside.  Use your electric mixer to beat together the butter and both sugars for a good 3 minutes until very fluffy, making sure to scrape down the bowl at least once.  Add in the egg, sesame oil, water and vanilla and beat again.

Add in all of the dry mix and mix on low until just combined.  Scrape down the bowl, add in the chocolate and mix again.  Weigh out 85 gram portions, roll each into a ball and then roll in a bowl of mixed black and white sesame seeds.  Place on your prepared pans with a few inches between each cookie ball.

Bake for 9 minutes, put on your oven mitts, reach in the oven and grabbing both sides of the pan give it a good tap on the rack so that all of the baking cookies flatten.  Bake for another 5 plus minutes until the cookies are all spread out and the edges are a lovely crispy golden brown but the centers are lighter – you may need another couple of minutes of baking time, you may also wish to tap them again.

When the cookies are baked to a done-ness of your liking, allow them to cool completely on the pan before attempting to move them.