4 cups flour
1 1/2 tablespoons coarsely ground black pepper
2 teaspoons baking powder
2 teaspoons kosher salt
1 cup grated Asiago cheese
1 cup grated pecorino Romano
12 tablespoons (1 1/2 sticks) cold unsalted butter, cut into 1/2-inch pieces
1 cup thinly sliced almonds
3 large eggs lightly beaten, plus 1 large egg, lightly beaten, for brushing the dough
1 cup whole or 2 percent milk
Combine the 3 beaten eggs and the milk in a measuring cup, then add to the food processor bowl, pulsing as you pour. Process just until the egg mixture and nuts are incorporated and the dough begins to form a ball.
Turn out the dough onto a large piece of wax paper, patting it into a disk. Wrap the disk in the paper and refrigerate for at least 2 hours and up to overnight.
Position oven racks in the middle and lower third of the oven; preheat to 350 degrees. Line 2 rimmed baking sheets with parchment paper or silicone liners.
Remove the dough from the refrigerator; if it is very firm let it sit at room temperature for about 15 minutes. Divide into 4 equal pieces. Roll each piece into a log about 11 inches long, 2 inches wide, and 3/4-inch to 1-inch thick. Place 2 logs on each baking sheet, spaced at least 1 inch apart. Use a pastry brush to lightly brush the tops of the logs with the remaining beaten egg, if using.
Reduce the oven temperature to 325 degrees. Working with one log at a time, place it on a cutting board and use a serrated knife to cut crosswise on the diagonal with a slow, sawing motion into 1/3-inch-thick slices, arranging them closely together on the baking sheets as you go. Bake both sheets for 15 minutes (on the middle and lower racks), then rotate them from top to bottom and front to back; bake for 15 minutes, until the biscotti are golden and crisp. Transfer to a wire rack to cool completely.
Recipe adapted from The Washington Post 2009