Peel the mango and remove the flesh from the pit. Puree all ingredients except fish sauce in a food processor or blender and process until completely smooth.
Pour into a saucepan over medium heat. Bring to a boil, reduce heat to low and continue to cook until the mixture thickens slightly.
Taste and add more sugar or vinegar as desired. Stir in the fish sauce, remove from heat and allow to cool.