1. In a saucepan place the pork, water, salt, soy sauce and garlic; heat to a boil. Reduce the heat cover and simmer until the meat is tender (50 minutes). Discard the garlic. Strain the liquid and set aside.
2. In a saucepan mix sugar, cornstarch, vinegar and pineapple juice until smooth. Gradually add the reserved liquid and cook stirring until the sauce is thick and transparent.
3. Add the pork, pineapple and sherry. Serve warm with cooked white rice.