Preheat oven to 350 degrees F. Line a baking sheet with parchment paper or a silpat mat.
Make flax egg by combining the ground flaxseed and water in a medium bowl. Let it sit for 5 minutes to thicken up. To the bowl with the flax egg, add the tahini, coconut sugar, and coconut oil. Stir until well combined.
Add the almond flour, coconut flour, baking soda, and salt. Mix well with a spatula. Fold in the chocolate chips. Let it sit for 5 minutes.
Use a cookie scoop and place on baking sheet. Flatten slightly with your hands. Bake for 9-11 minutes. Just until slightly golden. Let it sit on the pan for 10 minutes, then transfer to a cooling rack. They firm up once cooled. Enjoy!