Peppery Duck Fat Cookies

TO RENDER THE HERBED DUCK FAT (You can also use duck fat left from making duck confit, and omit this step): Combine duck skins/fats, sage, bay leaves, thyme, rosemary, and garlic in a pot, and set it over medium-high heat. Once the mixture has come to a sizzle, lower the heat down to medium-low. Stir occasionally and cook until all the oil from the skins/fats is rendered out (the skins/fats will become browned cracklings). Strain and chill the duck fat in the fridge until solidified.
TO MAKE THE PEPPERY DUCK FAT SHORTBREAD DOUGH: In a food processor, add herbed duck fat, unsalted butter, sea salt, ground white pepper, and ground black pepper. Run until the mixture is creamy and fluffy, approximately 2 minutes. Then add the all-purpose flour, Parmesan, and chili flakes, and pulse/run until a cohesive dough has come together.
Transfer the dough onto a piece of parchment paper. Dust it lightly with flour, then roll it into a thick log. Wrap tightly and freeze until firm.
TO BAKE THE SHORTBREAD: Preheat the oven on 325u0b0 F (165u0b0 C). Unwrap the shortbread dough, then cut into 1/4 inch-thick slices, and transfer it onto a parchment-lined baking sheet (sprinkle with extra chili flakes if you'd like). Bake for 20 to 25 min until slightly browned, then let cool completely on a cooling rack.