Cut pork belly into 3/4 in. (2 cm) cubes, slicing through the skin, fat and meat. Bring a pot of water to a boil. Working in batches, blanch the pork belly cubes 2 to 3 min., until the pork turns lighter-coloured and opaque. Transfer blanched pork into a colander. Rinse with cold water. Pat dry with paper towels; set aside.
Heat the canola oil in a large pot (with lid) over medium heat. Lightly brown the pork belly cubes on all sides. Reduce the heat to low, add the 5 spice and sugar, stirring to coat evenly. Cook 2 to 3 min. to lightly brown the sugar. Stir in the cooking wine and soy sauces to coat the pork. Add the garlic, ginger and broth to the pot. Cover and gently simmer for 1 hr., or until pork belly is fork tender. Stir occasionally to prevent scorching.
Remove the lid. Increase heat to high. Cook, stirring often, until the sauce reduces to a glistening coating on the pork belly.
Transfer to serving platter. Garnish with green onions.