COMBINE salsa and 2 cups of the water in large saucepan. Bring to boil.
MEANWHILE, mix stuffing mix, meat, onions, eggs, mint, cilantro, garlic and remaining 1/2 cup water in large bowl. Shape into 24 balls, about 1/4 cup each. Drop meatballs gently into boiling salsa mixture; cover.
REDUCE heat to medium. Simmer 18 to 20 min. or until meatballs are cooked through (165°F).
STIR cheese into mashed potatoes just before serving. Top potatoes with hot meatballs.