1/4 pound (1 stick) unsalted butter
3 ounces grated Parmesan
1 1/4 cups all-purpose flour
1/4 teaspoon kosher salt
1 teaspoon chopped fresh thyme leaves
1/2 teaspoon freshly ground black pepper
Place the butter in the bowl of an electric mixer fitted with a paddle attachment and mix until creamy. Add the Parmesan, flour, salt, thyme and pepper and combine.
Dump the dough on a lightly floured board and roll into a 13-inch long log. Wrap the log in plastic wrap and place in the freezer for 30 minutes to harden.
Meanwhile, preheat the oven to 350 degrees F.
Cut the log crosswise into 1/4 to 1/2-inch thick slices. Place the slices on a sheet pan and bake for 22 minutes.