01 - Preheat the oven to 320°F.
02 - Remove excess fat from the duck cavity and pat dry with paper towels.
03 - Combine five-spice powder, sea salt, and black pepper; rub evenly over the duck, including inside the cavity.
04 - Fill the cavity with crushed garlic, sliced ginger, and scallion pieces.
05 - Place the duck breast-side up on a wire rack set in a roasting pan and roast for 1 hour.
06 - Combine soy sauce, honey, and rice vinegar in a small bowl.
07 - Raise oven temperature to 430°F. Brush the duck with the honey-soy glaze.
08 - Return the duck to the oven, roast for 20 to 30 minutes, basting once halfway through, until skin is deep golden and crisp.
09 - Remove the duck from the oven and allow it to rest for 10 minutes before carving.
10 - Serve slices with Mandarin pancakes or steamed buns, cucumber, scallion, and hoisin or plum sauce.