In a wide, heavy-bottomed pan over medium heat, heat oil. Add onions and garlic and cook, stirring regularly, until softened.
Add pork and cook until lightly browned.
Add vinegar and bring to a boil, uncovered and without stirring, for about 3 to 5 minutes.
Add water, salt, bay leaves, and peppercorns. Stir to combine. Continue to boil for about 3 to 5 minutes.
Lower heat, cover, and continue to cook for about 40 to 50 minutes or until meat is fork-tender and liquid is reduced.
Add sugar and stir. Continue to cook, uncovered, until mixture begins to render fat.
Sprinkle with fried garlic bits as desired and serve hot.