I love shortbread. And walnuts. And sage. So why not put them all together? These cookies kind of skate on the edge of sweet and savory—a little sugar, a little salt, a little black pepper. They're really easy. And good with champagne!
Place toasted walnuts in work bowl of a food processor and pulse till walnuts are the consistency of cornmeal. Add flour, salt, pepper, sugar and sage, and pulse till blended. Add butter; pulse until dough comes together. Shape the dough into a log about 1 1/2 inches in diameter, and wrap with plastic wrap. Chill until firm enough to slice, about 30 minutes or overnight.
Heat oven to 350°F and place a rack in the center of the oven . Line a baking sheet with parchment. Cut the dough log into 1/3- to 1/2-inch-thick rounds; place on sheets. Bake 10 minutes. Reverse sheets front to back. Bake until cookies are golden, about 15 minutes longer. Cool thoroughly on cooling rack.