Combine the salt, black pepper, bay leaves, garlic and vinegar in a large nonreactive pot or enameled Dutch oven. Nestle the pork belly into the pot, skin side down, and then pour in enough water so that the liquid comes halfway up the pork belly. Bring the pot to a boil over high heat, and then cover and gently simmer over very low heat for at least 3 hours, turning the pork belly over once midway through simmering.

Sauté garlic and onion in hot oil until onion is transparent. Combine pork belly, salt, coarse pepper, fine pepper, and patis and cook for 5 minutes. Add soy sauce, vinegar, laurel leaves, and water, then bring to a boil. Covering the pot, cook for 10 minutes, then simmer for another 10 minutes. Serve hot.