In a large pot or deep pan, heat some cooking oil over medium heat. Brown the pork pieces on all sides until they are lightly caramelized. Remove and set aside.
In the same pot, sauté the garlic and onions until fragrant and translucent.
Return the pork to the pot and add the soy sauce, vinegar, water, bay leaves, peppercorns, and brown sugar. Stir well to combine.
Bring the mixture to a boil, then reduce the heat to low. Cover the pot and simmer for about 1 to 1.5 hours until the pork is tender and fully cooked. Stir occasionally to prevent sticking.
Taste the sauce and adjust the seasoning with salt and more sugar, if desired. Simmer for an additional 5-10 minutes to let the flavors meld together.
Once done, remove the bay leaves and transfer the Paksiyo Baboy to a serving dish.
Garnish with some sliced green onions or chili flakes for added flavor and presentation.
Serve hot with steamed rice and enjoy!