In a small mixing bowl, combine the rice flour, sorghum flour, millet flour, arrowroot starch, baking soda, and salt. Stir until the ingredients are well blended together. Set aside.
In a new mixing bowl, combine the sugar, ghee, and water. Cream together for 1 minute.
Add the egg and vanilla extract. Beat for 1 minute.
Add the flour mixture to the egg mixture.
Stir until all of the flour is incorporated and a dough forms.
Chill the dough in the refrigerator for at least 60 minutes (up to over night).
Preheat the oven to 350°F. Line a baking sheet with parchment paper.
Roll the dough out to 1/8 – 1/4 inch thick.
Cut the dough into fun shapes.
Bake for 8 – 10 minutes.
Let the cookies cool on a baking sheet for 5 minutes before transferring them to a cooling rack.