Combine the pork, onions, garlic, and water to cover by 1 in/3 cm. Bring to a boil, and then reduce the heat to simmer gently for 30 minutes, skimming frequently. Adjust seasoning with salt as needed.
Add the chicken and simmer until all the meat is tender, about 45 minutes. Add water as needed to keep covered by ½ in/1 cm.