1) Preheat the oven to 400°F. Line a baking sheet with parchment, or leave it bare; no need to grease it.
2) Blend together the flour, baking powder, xanthan gum, and salt.
3) Work the cold butter into the dry ingredients until the mixture is crumbly.
4) Stir in the chives, sun-dried tomatoes, and cheese.
5) In a separate bowl, beat together the eggs and milk.
6) Add the liquid ingredients to the dry ingredients, stirring just until a cohesive dough forms; it'll be sticky.
7) Using a muffin scoop or large spoon, scoop the dough in 1/4-cupfuls onto the prepared baking sheet; you should have 10 mounds of dough. Press them down gently to flatten slightly. Allow the biscuits to rest for 10 to 15 minutes.
8) Bake the biscuits for 15 to 20 minutes, or until they're golden brown. Remove them from the oven, and serve warm, or at room temperature. Store at room temperature for several days; freeze, well-wrapped, for longer storage.
Yield: 10 biscuits.