For the best results make 125 g brown butter using 140 g butter as per step 2. If want to skip this step, please jump onto step 3.
Heat butter in a saucepan on medium heat, first it will melt then it will foam. It is ready when the white bits on the bottom of the pan will turn into golden brown and it has a nutty smell. Make sure you carefully watch it throughout the process, stir regularly and remove from the heat before it starts burning. Let it cool to room temperature.
With an Electric hand mixer mix the browned butter and sugar together just until well combined.
Mix in the egg, do not overmix or it will become rather like a cake, not cookie.
Sift the two different kinds of flour, salt and baking soda together then add the flour mixture into the dough, fold with Rubber spatula
Before the flour mixture fully combined into the dough add in the chocolate chunks or substitute chocolate with hazelnut, almond, pistachio etc.
Divide the dough into 10 equal balls (using a Digital scale is handy, approx. 70g each) and place them on parchment paper leaving enough space between them to spread. Do not soften the surface of the ball, in fact try to keep it as rough as possible for a nice, crackly surface. Let them rest in the fridge for an hour or two.
Pre-heat oven to 180 C / 356°F
Remove the cookie balls from the fridge and Bake the cookies as per following: At 11 minutes take the tray out and bang the tray to the kitchen counter and apply circular movement around them with the help of a cookie cutter (as explained in the Tips section above). Continue to bake for 5 more minutes. Overall the cookies require 16 minutes baking in 180C. The cookies might look under baked however they will set as they cool
Sprinkle them with salt flakes to enhance taste