For the pork belly:
Cut it into pieces of approximately 10x15 cm.
Introduce the pork belly on a pot with water, the soy sauce, the maple syrup and the sesame oil and cook it at maximum heat until boiling. At this moment, turn the heat down to ¾ of the power and cook it without letting the water boil for 90 minutes (or for the oven, at 100º C for 4 hours - in this case, we use a metal oven-safe pot with a top). Let the pork belly stand in the broth for 6 to 8 hours.
For the sauce
Strain the broth from the cooking of the pork belly and reduce it at high heat until it has the texture of a sauce.