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.
03 - Add cold butter cubes. Using a pastry cutter or your fingertips, cut butter into flour mixture until it resembles coarse crumbs with some pea-sized pieces.
04 - Stir in grated Gruyere and chopped sage.
05 - Pour in cold buttermilk and mix gently with a fork until dough just comes together—do not 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, pressing straight down without twisting. Gather scraps and repeat.
08 - Place biscuits on prepared baking sheet, 1 inch apart. Brush tops with milk or cream if desired.
09 - Bake 14–16 minutes, until golden brown.
10 - Cool slightly and serve warm.