2 cups cake flour (all-purpose flour will work too)
1 tablespoon baking powder
1/2 teaspoon baking soda
1 scant teaspoon fine grain sea salt (table salt works too!)
1 1/2 stick (6 ounces) unsalted butter, cold
1 cup fontina cheese, grated
3 tablespoons fresh sage (about 6-7 fresh sage leaves), minced
Freshly ground pepper
1/2 cup buttermilk, cold and shaken
1 large egg, cold
1 large egg
1 tablespoon milk (or 1 tablespoon water)
1. Preheat oven to 400F. Line a baking sheet with parchment paper and set aside.
2. In a large bowl, mix together the dry ingredients: all-purpose flour, baking powder, baking soda and salt. Using a box grater, grate the butter into the flour mixture. Transfer the bowl to the freezer while you gather the wet ingredients, about 5-7 minutes.
3. Measure out the buttermilk and add the egg; whisk until combined. In a small bowl, make the egg wash, whisking together the egg and milk. Transfer both to the refrigerator.
4. Grab the bowl out of the freezer, and gently break up the butter and combine with the flour, using your hands, until it resembles small peas. Add the fontina cheese and minced sage and toss to combine thoroughly. Add the buttermilk mixture all at once to the flour mixture. Mix until barely combined; lightly knead the dough until it forms into one solid mass. Sprinkle your kitchen counter with flour and dump the dough onto it. Press the dough into a 1/2-inch thickness. Cut out the biscuits using a 2-inch biscuit cutter, ending up with about 6 biscuits. If you like, you can recombine the scraps and get 2 more biscuits. Transfer them to the baking sheet. Brush each biscuit with the egg wash and top with a few turns of freshly ground pepper.
5. Bake for 10-12 minutes and until lightly golden brown. I think biscuits should be served warm...with butter.