Add pork belly to a medium-sized pot and cover with water. Bring to a boil and allow it to boil for a few minutes. Drain the pork belly and rinse the pot and the meat well to remove the impurities. Return the pork belly to the cleaned pot.
In a small saucepan, add sugar and 1 teaspoon water. Without stirring, allow the sugar to melt over medium heat. Once the sugar has completely melted, begin stirring occasionally and allow the mixture to simmer until it caramelizes into an amber color. Remove from heat immediately and add the caramel sauce to the pot with the pork belly. Mix well until the pork is covered in sauce.
Add hard boiled eggs, coconut water, fish sauce and garlic, with just enough water to cover the pork belly.
Bring to a boil, then simmer over medium heat for 1 hour.
At this point, the pork belly should be about ¾ covered in liquid. If there's not enough, add more water. Add in the scallions and simmer for another 30-60 minutes, until the pork belly is soft and tender.