Slice pork belly into 1.5-inch cubes. Toss with soy sauce, vinegar, smashed garlic, bay leaves, and whole black peppercorns in a bowl. Let sit at room temperature for 30 minutes.
1.5 lbs pork belly, 0.5 cup soy sauce, 0.25 cup vinegar, 6 cloves garlic, 3 bay leaves, 1 tsp black peppercorns
Heat oil in a heavy-bottom pot or Dutch oven over medium-high heat. Remove pork from marinade (reserve the liquid). Sear pork pieces 3-4 minutes per side until golden and caramelized.
1 tbsp oil, 1.5 lbs pork belly
Pour the reserved marinade, sliced onion, water, and sugar into the pot. Bring to a boil, then reduce heat to low. Cover and simmer for 60-75 minutes, stirring every 20 minutes, until pork is fork-tender.
0.5 cup soy sauce, 0.25 cup vinegar, 1 medium onion, 0.5 cup water, 1 tbsp sugar
Remove the lid and increase heat to medium. Simmer uncovered for 10-15 minutes until the sauce thickens and coats the back of a spoon and pork edges crisp slightly.
Turn off heat and let pork rest in the pot for 10 minutes to allow the sauce to thicken further and the flavors to settle.
