01 - Preheat oven to 425°F. Line a baking sheet with parchment paper.
02 - In a large bowl, whisk together flour, baking powder, baking soda, salt, and pepper until well blended.
03 - Add cold butter cubes to flour mixture. Using a pastry cutter or your fingertips, cut butter into flour until mixture resembles coarse crumbs with some pea-sized pieces remaining.
04 - Stir in grated Gruyere cheese and chopped fresh sage until evenly distributed throughout the flour mixture.
05 - Pour cold buttermilk over mixture and mix gently with a fork until dough just comes together. Do not overmix—some dry spots are acceptable.
06 - Turn dough onto a lightly floured surface. Pat gently into a 1-inch thick rectangle, being careful not to overwork the dough.
07 - Using a floured 2.5-inch biscuit cutter, cut straight down through dough without twisting. Press firmly and lift. Gather scraps and repeat until all dough is used.
08 - Place cut biscuits on prepared baking sheet, spacing 1 inch apart. Brush tops with milk or cream if desired for enhanced browning.
09 - Bake for 14 to 16 minutes until biscuits are golden brown on top and cooked through.
10 - Cool biscuits slightly on baking sheet before serving warm.