In a mixing bowl, combine the cut pork belly pieces with 1 tablespoon of low-sodium soy sauce and let marinate for 5 minutes.
To prepare the sauce, in a small bowl, combine 3 tablespoons of low-sodium soy sauce, 3 tablespoons of kecap manis (Indonesian sweet sauce), 1 tablespoon of shaoxing wine, and 1 tablespoon of sesame oil and mix well. Set aside.
Heat 1 tablespoon of canola oil on a frying pan over medium high heat. Add the marinated pork belly and cook for about 3-4 minutes, until no longer pink and cooked. Pour in the sauce mixture and 1/2 cup of water and stir to mix. Cover the pan with a lid and lower heat to medium. Let simmer for about 5 minutes. Remove the lid and simmer for another 15 minutes, until the pork belly turns rich brown in color and the sauce reduces and darkens in color.
Transfer to a serving bowl and top with green onions.