Preheat oven to 375 °F/190°C.
Line a baking sheet with parchment paper.
Make sure all your ingredients are at room temperature.
In a large bowl mix together the butter, tahini and Swerve Brown sugar-free sweetener, whisk to homogenize, add the egg and vanilla extract, and whisk one more time to infuse the egg with the mix.
Stir in the almond meal, chopped walnuts, if used, baking powder, baking soda and salt, give a quick stir with a spatula until you end up with a sticky dough.
Add the chocolate chunks and fold them in the dough, cover with cling film and refrigerate for 30 minutes.
Scoop the tahini cookie dough, using a tablespoon, for 12 equal pieces. Roll them into equal balls, you can add some more chocolate chips on top of the balls.
Place them on the lined cookie sheet, bake in the preheated oven for 9 to10 minutes, or until the edges are slightly browned, keep them on the baking until they're totally cooled. Transfer to a serving plate and enjoy.