In a wide pan over medium heat, heat oil. Add onions and garlic and cook until softened.
Add pork and cook, turning as needed, until lightly browned. Cook, stirring occasionally, for about 7 to 10 minutes.
Add chicken and cook, stirring occasionally, until lightly browned and juices run clear.
Add vinegar and bring to a boil, uncovered and without stirring, for about 2 to 3 minutes.
Add soy sauce, water, and bay leaves. Continue to boil for about 2 to 3 minutes, skimming scum that floats on top.
Lower heat, cover, and cook for about 30 to 40 minutes or until meat is tender and sauce is reduced.
Season with salt and pepper to taste. Serve hot.