Preheat the oven to 425°F.

In a large bowl, whisk together the flour, xanthan gum, salt and baking powder. Use a pastry cutter to cut the butter into the flour mixture until it resembles coarse cornmeal.

Stir in the milk until incorporated. You may need an additional 1-2 tablespoons of milk to insure all the flour is moistened. Form the dough into a ball and knead about 10 times in the bowl.

Roll the dough out on a floured board to desired thickness (biscuits will not rise much while baking). I roll the dough to about 1 ½ - 2 inches thick. Use a 2 inch biscuit cutter to cut the biscuits. Gently re-roll dough as needed.

Place biscuits on an ungreased baking sheet and refrigerate for 30 minutes (uncovered) before baking. You can also make the dough a few hours ahead of time and leave refrigerated until ready to bake.

After 30 minutes chilling, bake 12-15 minutes or until done (cooking time will depend on thickness of the biscuit). Serve warm.

Store leftovers in an air-tight container or bag overnight or freeze.