Use a pair of scissors to cut open the duck cavity (slightly off the center in between both of the breasts). Trim off any unwanted parts such as the connective tissues, the huge piece of the neck skin, the butt, and some duck fat.
Rinse the duck thoroughly under running water. Use paper towels to absorb the moisture.
Put the duck on a big try, skin side up. Flatten the duck by pressing it down firmly. You should be able to hear a few cracking sounds when you break up the thigh, ribs and clavicles.
Coat the duck with a large amount of coarse sea salt. Don’t worry that it be will too salty because it is coarse salt, it doesn’t dissolve easily. Tomorrow we will rinse off the salt as well.
Put a flat board on the duck then weigh it down with a huge pot that is filled with water. Set it in the fridge for 12 hours. The purpose of the salt and the pressure is to press the moisture out of the duck. Later on, when we braise it, it will absorb the flavor from the brine.
The next day, rinse the duck thoroughly with some boiling hot water. This will shrink up the skin and wash off all the salt so the duck will not be too salty. Wipe off the moisture with a paper towel.
Preheat the oven to 450 F. Place the duck on a rack on top of a baking pan.
Heat a heavy-duty cast-iron skillet until smoking hot. Flip the skillet over and apply a thin layer of oil at the bottom.
Put the duck into the oven and place the hot heavy skillet right on top of the duck. Bake for 30 minutes to render the fat.
While waiting, we can prepare the braising brine. Add oil to a large pot. Add all the dried spices along with the ginger slices, garlic cloves, and scallions. Stir over medium heat for a couple of minutes or until fragrant.
Add 5-6 cups of bottled water or distilled water then bring to a boil. Do not use tap water as it will ruin the quality of your Lushui (卤水).
Add soy sauce, dark soy sauce, Chinese cooking wine, and rock sugar. Simmer for 15 minutes. Chinese master sauce is supposed to be a lot saltier than your normal taste so it can infuse its flavor into the ingredients you want to cook in it.
Take the duck out of the oven and remove the cast iron skillet. You should be able to see lots of greases formed in the banking pan. If you don’t have a cast-iron skillet, you can wrap a heavy-duty brick with tin foil. Preheat it until hot and place it onto the duck.
Transfer this duck into the braising brine (you can cut the duck smaller if your pot doesn’t fit). Braised on low heat for 1 hour.
Transfer the duck onto a baking rack - skin side up. Stick it into the oven again. Set the temperature at the lowest. Let it dehydrate for 6-8 hours. The time varies depending on your oven’s minimum temperature. Enjoy!
You can store the brine for future use. Check this video to learn more about Lushui (卤水) - https://youtu.be/umdrNXXz5qo