Remove the duck from the package and pat dry with paper towels. Remove the innards and set aside (save these for making duck broth). Place in a large roasting pan.
In a small bowl, combine the salt, garlic, five spice, and Szechuan peppercorn and mix together. Rub the mixture on all sides of the duck.
Place the quartered orange pieces inside the cavity of the duck. Place in the fridge, uncovered, overnight.
Remove the duck from the fridge and let it come to room temperature for about 30 minutes. Preheat the oven to 425 degrees.
Place the duck on on a roasting rack, breast side up, in the roasting pan, This helps to keep the skin crispy on all sides. Place the roasting pan on the middle rack in the oven.
Cover with foil and roast for 40 minutes. Remove and baste with the rendered fat in the bottom of the pan. Be careful as it will be hot.
Place back in the oven and roast another 30 minutes. Remove the foil for the last 20 minutes.
Remove the duck from the oven and spoon out all the duck fat (see note 6). Brush the duck with the glaze.
Place back in the oven for 10 minutes. Remove and brush with glaze again. Place back in the oven for another 10 minutes. Remove from oven and let the duck rest for 10-15 minutes.
Carve and serve plain or drizzled with remaining orange sauce.
Combine all the glaze ingredients in a medium saucepan and bring to a boil, stirring periodically. Turn the heat down to medium and simmer 20-30 minutes, or until the sauce has been reduced by half.
It's important to let the duck sit in the fridge overnight so the moisture can evaporate from the skin - this is how we get the crispy skin.
To roast the peppercorns, place them in a skillet and heat over medium heat. Shake the pan every minute or so to prevent burning. Once they become fragrant (3-5 minutes), remove from heat. Grind the peppercorns with a mortar and pastel or a spice grinder.
Dry sherry can be used as a substitute for the Shaoxing wine.
I HIGHLY recommend using a roasting rack to roast the duck. This keeps the skin crispy and makes it easier to spoon the duck fate out of the pan.
The internal temperature of the duck should reach 165 degrees. It's ok if the meat is slightly pink, as long as it is cooked to temperature.
Save the duck fat in a container and store in the fridge for 2-3 months. It can also be frozen in ice cubes and stored for up to 6 months in the freezer.
To reheat: place leftover duck in a roasting pan and place in a 350 degree oven for 10 minutes, until warmed through. It can also be reheated in the microwave.