Blueberry Scones

source: https://www.mamaknowsglutenfree.com/gluten-free-blueberry-scones/

1/2 cup butter, diced and really cold (freeze for 10 min)
3 cups gluten-free all-purpose flour
3/4 teaspoon xanthan gum
1/3 cup granulated sugar
1 t baking powder
1/2 salt
1 T lemon zest
3/4 cup buttermilk
2 large eggs, whisked
1/2 cup sourdough starter
1 cup fresh or frozen blueberries
2 tablespoons milk

Freeze butter. Make buttermilk by adding 2T of vinegar to 3/4 milk. Put all dry ingredients in a bowl. Add starter and liquids.