Preheat an oven to 275 degrees.
Place all ingredients from pork belly to 3 1/2 cups water into a baking dish. Cover and cook in the oven for 3 hours until tender.
Remove the pork from the pan and cool.
Strain the braising liquid and skim off all of the fat. Place the liquid in a pot, add the sugar, and reduce by half.
Mix the cornstarch and the water. Mix the slurry into the braising liquid and simmer for 1-2 minutes.
Cut the pork belly into desired portions size and pat dry. The pork needs to be as dry as possible or it will not get a good sear. Heat a large skillet with some oil over medium-medium/high heat. Sear all sides of the pork belly until golden brown and serve with the sauce.