Preheat the oven to 350° F.
Grease a baking sheet with a bit of butter.
In a mixing bowl, cream together the butter and erythritol.
Add the lemon juice, eggs, and chia seeds and mix well.
Add the almond flour, coconut flour, and baking soda and mix well.
Form into a 1" thick round on the baking sheet. Cut into 6 triangles.
Bake for 30-35 minutes, or until golden brown and cooked through. About 3/4 of the way through baking, you can separate the scones on the baking sheet to let them cook more evenly.