Prepare the seasoning rub by mixing together 1 tbsp kosher salt, ½ tbsp white pepper, ½ tbsp five spice powder, ½ tbsp sugar, and 1 tbsp shaoxing wine.
Rub the seasoning all over the pork belly, including the skin.
For the crust, mix together 1 cup kosher salt, 1 beaten egg white, and 1 tbsp white vinegar.
Spread the salt mixture evenly over the pork belly skin, pressing it in to adhere.
Place the pork belly on a rack and refrigerate uncovered for at least 4 hours, or up to 24 hours.
Preheat the oven to 400°F (200°C).
Roast the pork belly for 45-60 minutes, or until the skin is crispy and golden brown.
Let the pork belly rest for 10 minutes before slicing and serving.
