Your Pork Belly (3 pound) should have a layer of skin, fat, meat, fat then meat.
Boil the Fresh Ginger (2 slice) and Scallion (2) in water for a few minutes to extract the flavor. Add in the belly and cook for 7 minutes at medium high with lid on. Prepare a dish with Water (to taste) to place the pork belly in after.
Cool the pork belly in ice water, making sure it's completely cool inside. Once cool, use a knife to scrape the skin off, and wash away any remaining residue.
In a bowl mix the spice rub: Salt (1 tablespoon), Ground White Pepper (1/4 teaspoon), Ground Ginger (1/4 teaspoon), Garlic Powder (1/2 teaspoon), Chinese Five Spice Powder (1 1/2 teaspoon), and Granulated Sugar (1/2 tablespoon).
Tape a bunch of skewers together and stab the skin with it. Don't stab too deep, just 3-5mm in depth.
With wet hands, rub Baking Soda (3/4 teaspoon) on the skin. Leave it to rest for 30 minutes. This helps soften the skin.
Slice the meat side of the belly twice, but not all the way through. Only about halfway.
Rub the spice everywhere except the skin.
Let the pork rest, skin side down, on paper towels.
If using, rub some Rice Wine (1 teaspoon) on the meat side of the pork. Poke the skin with skewers again.
Mix the Sweetened Condensed Milk (1 1/2 tablespoon), Distilled White Vinegar (1 tablespoon) and Water (3 cup). In a pan that fits the belly, pour the mixture. Lay the pork skin side down and leave for 15-20 minutes.
Transfer to a pan and air dry the skin. Do not pat dry. Store overnight uncovered in the refrigerator.
The skin should be dry like this. Before roasting, preheat the oven at 350 degrees F (180 degrees C).
In a roasting pan with a drip pan underneath, roast for 20 minutes.
Turn the heat up to 400 degrees F (200 degrees C). Roughly stab the skin one last time to bring the oil out.
Place the meat, skin side up, in aluminum foil, and wrap it up making sure to keep the skin side open.
Roast again for 30 minutes.
If the skin does not look like this, roast for 5 more minutes or use a broiler.
Slice along the halfway cut and enjoy!