01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - In a large mixing bowl, whisk together flour, baking powder, salt, and black pepper until thoroughly mixed.
03 - Incorporate the cold, cubed butter into the flour mixture using a pastry cutter or fingertips until the mixture resembles coarse crumbs.
04 - Stir in the grated cheddar cheese and finely chopped chives until evenly distributed.
05 - Whisk together milk and sour cream in a separate bowl. Pour into dry mixture and mix gently just until the dough comes together without overmixing.
06 - Transfer dough onto a lightly floured surface and gently pat into a 1-inch thick circle.
07 - Cut dough into 8 wedges. Place wedges on the prepared baking sheet. Brush tops with a small amount of milk.
08 - Bake for 16 to 18 minutes, until golden brown and set through.
09 - Allow scones to cool slightly on a wire rack before serving warm.