Check your pork belly. If the top fat layer is too thick for your tastes then cut some off before curing.
Cure pork belly by mixing 1/8 cup each of sugar and salt and sprinkling it evenly on all sides. Cover and set in the frig for 24 hours.
After 24 hours, remove from frig and quickly rinse the salt/sugar off of the meat and pat dry. Score the fat in a hatch mark pattern.
Put in a roasting pan, cover tightly with foil and roast at 325 degrees Fahrenheit for 1 hour. Remove foil and turn oven to 350 degrees and roast for another 30-45 minutes until the fat has a light golden color.
Remove from oven and allow to cool for 15 minutes. Place meat on a small foil lined sheet pan and lightly cover with plastic wrap and then a piece of foil and top with a heavy cast iron skillet (or anything heavy and clean, if you don’t have a heavy pan) then place in the frig overnight to 24 hours. This step is to press the meat, so it is compact.
When you are ready to make the ragout, take out the meat and cut into about 1/2 to 3/4 inch cubes.
In a sauté pan, add 1 tablespoon of oil and add chopped onions and garlic with the 1/2 teaspoon of salt to sweat (about 5 minutes)
Add the grounded/pounded Gochugaru, Szechuan peppercorn and dry Thai chili’s to the onion mixture and stir well.
Then add the chili bean sauce, soy sauce, sugar and stock and mix well.
Add the cubed pork belly and give it a good stir then let it simmer on low heat for 30 minutes.
Remove from heat and cool for about 15 minutes, then place in a container and let it sit in the frig overnight (or for at least 8 hours).
The day you want to eat, make the bao buns and steam (if using).
In the meantime, make simple slaw by mixing sugar and vinegar and adding it to the cucumber, carrots, red pepper and green onion, combine well. Let sit for 15 minutes.
Remove the meat mixture from frig and warm up.
Now you are ready to assemble. Add about 2 tablespoons of pork filling into the opening of a bao bun and top with some pickled slaw, chopped cilantro and peanuts.