• 3 cups all-purpose flour
• 2 oz. Parmesan cheese, grated on smallest holes of a box grater (about 1/2 cup)
• 1/4 cup sliced fresh chives, plus more for garnish
• 1 tablespoon baking powder
• 1 teaspoon black pepper
• 3/4 teaspoon kosher salt
• 3/4 teaspoon garlic powder
• 3/4 teaspoon baking soda
• 1 3/4 cup whole buttermilk
• 3 tablespoons whole-grain mustard
• 3/4 cup unsalted butter, frozen, plus melted butter for serving

Preheat oven to 475 degrees.  Stir together flour, cheese, chives, baking powder, pepper, salt, garlic powder and baking soda in a large bowl.  Whisk together buttermilk and mustard in a small bowl.  Grate frozen butter into flour mixture using the largest holes of a box grater; stir until well coated.  Add buttermilk mixture; stir until just combined.

Drop batter in 2 1/2 to 3 tablespoonful rounds onto two baking sheets lined with parchment paper, leaving 3″ between rounds.

Bake in preheated oven until biscuits are golden brown (14 to 18 minutes), rotating baking sheets between top and bottom racks halfway through baking time.  Brush biscuits with melted butter; garnish with sliced chives.  Serve warm.