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 combined.
03 - Add cold butter cubes. Using a pastry cutter or fingertips, cut butter into flour mixture until it resembles coarse crumbs with some pea-sized pieces remaining.
04 - Stir in grated Gruyere and chopped sage until evenly distributed throughout the flour mixture.
05 - Pour in cold buttermilk and mix gently with a fork until dough just comes together. Be careful not to overmix.
06 - Turn dough onto a lightly floured surface. Pat into a 1-inch thick rectangle.
07 - Using a floured 2.5-inch biscuit cutter, cut out rounds by pressing straight down without twisting. Gather scraps and repeat cutting.
08 - Place biscuits on prepared baking sheet, spacing 1 inch apart. Brush tops with milk or cream if desired.
09 - Bake for 14 to 16 minutes until biscuits are golden brown.
10 - Cool slightly and serve warm.