Preheat oven to 425º. Line a large baking sheet with parchment paper or a baking mat.
In a large bowl, whisk together the flour, baking powder, sugar, salt, and pepper.
Using a box grater, grate butter over the flour mixture and quickly toss with your hands to incorporate. Add the chives and feta cheese and quickly toss again to combine. If there are any large feta chunks, crumble them to be no larger than peanut-sized.
Using a small bowl or wooden spoon, make a well in the middle of the flour mixture and pour the buttermilk over. Stir until just beginning to come together, then dump out onto a floured work surface.
With floured hands, bring the dough together, and using a lightly floured rolling pin gently roll into a rectangle, about 1” thick.
Fold the dough in half and turn once. Using a rolling pin, gently pat back into a 1” thick rectangle, and repeat the folding process two more times.
Roll the dough into a 1” thick rectangle. Using a 2½” round biscuit cutter, press down, but don’t twist! Cut out the biscuits and place them baking sheet, about a half-inch apart. Bring together dough scraps and cut out more biscuits.
Brush tops of biscuits with melted butter and bake for about 20 minutes, or until flaky and tops are lightly golden.
In a small bowl mix the cream cheese, lemon juice, and extra chives.
Serve biscuits warm with cream cheese and salmon lox or smoked salmon and sprinkle with pepper.