Mix together stevia, potato starch, almond flour, coconut flour, cocoa powder, beet powder, baking powder, and salt until combined.
Stir in coconut oil and egg until all dry ingredients are incorporated. If dough seems too wet (could be if eggs were too large), add coconut flour 1 teaspoon at a time, until dough pulling away from sides of bowl.
Shape dough into approximately 1 tablespoon sized balls. Roll into pistachios and press down slightly so they adhere, if necessary.
Place balls on ungreased baking sheet approximately 2 inches apart. Press down on cookie dough lightly with the bottom of a baking glass to flatten slightly.
Bake at 350 F degrees for 10 minutes. Let rest on pan for 2 minutes before removing with spatula to cool completely.