01 - Set the oven to 400°F and line a baking sheet with parchment paper.
02 - Whisk together the flour, baking powder, salt, and black pepper in a large bowl.
03 - Add cold, cubed butter to the flour mixture and rub in with fingertips or a pastry cutter until the texture resembles coarse breadcrumbs.
04 - Stir in the grated cheddar and chopped chives evenly throughout the mixture.
05 - Whisk the milk and egg together in a small bowl, reserving 1 tablespoon for brushing.
06 - Pour the remaining wet mixture into the dry ingredients and mix gently with a fork until just combined, avoiding overmixing.
07 - Transfer dough onto a lightly floured surface and pat into a 1-inch thick round.
08 - Use a 2½-inch round cutter to cut out the scones, reassembling scraps to use all dough.
09 - Arrange scones on the baking sheet and brush the tops with the reserved milk and egg mixture.
10 - Bake for 16 to 18 minutes until golden and risen.
11 - Allow scones to cool slightly on a wire rack before serving warm or at room temperature.