Sharp cheddar cheese is a good foil to the chives in these biscuits. Heat oven to 450°. Whisk together 2 cups flour, 2 tbsp. baking powder, 1 tbsp. sugar, 1 1/2 tsp. salt, and 1/2 tsp. baking soda in a bowl. Using a pastry cutter, work 8 tbsp. cold butter cut into thin pats into flour mixture until the butter is the size of small peas. Add 3/4 cup plus 2 tbsp. buttermilk, 1/2 cup shredded sharp cheddar cheese, and 1/2 cup finely chopped chives to flour–butter mixture; stir with a fork to form a loose dough. Turn dough out onto a floured surface; gently pat into a 6" × 9" rectangle. Fold in thirds as you would a letter; pat into a 6" × 9" rectangle again. Dip edges of a 3" round biscuit cutter in flour; punch out 6 biscuits from dough. Transfer them to a parchment paper–lined baking sheet. (Form and cut dough scraps into another biscuit or two, if you wish; they won't rise as high, though.) Brush tops with 2 tbsp. heavy cream; bake until lightly browned, 14–16 minutes. Makes 6.