Begin by thoroughly rinsing your duck under cold water, then pat it dry with paper towels. Using a sharp knife, carefully score the skin of the duck around the breasts to help render the fat. In a small bowl, combine softened butter with salt, granulated garlic, oregano, and thyme, creating a flavorful paste. Generously apply this mixture both inside and outside the duck, ensuring it’s well-coated, then cover the duck and let it rest for one hour to enhance the flavors.

While the duck is resting, preheat your oven to 400°F (200°C). Position your oven rack to accommodate the size of the duck, and prepare a casserole dish or roasting pan.

Once the oven is heated, place the duck breast side up in the prepared roasting dish. Bake it uncovered at 400°F for 30 minutes, then cover the dish tightly with foil, reducing the temperature to 360°F (182°C). Continue baking for an additional hour.

While the duck is baking, prepare the glaze. In a saucepan, combine soy sauce, Worcestershire sauce, brown sugar, and chicken broth over medium heat. Bring to a gentle boil, stirring frequently. Mix cornstarch with cold water to create a slurry, then whisk into the glaze once boiling and cook until thickened.

After the hour of baking, carefully remove the foil and check doneness using a skewer. The juices should run clear, and the internal temperature should reach 165°F (74°C). If necessary, return the duck to the oven for more cooking.

Once your roast duck is perfectly cooked, brush the warm glaze generously over the duck. Allow it to rest for 15 minutes before carving.