1) Bring water and sugar to a boil in a saucepan and cook until sugar is melted, stirring occasionally. Add the ginger and cook for 1 minute. Remove from the heat, stir in the mint and steep for 5 minutes.
2) Place the mango in a bowl, strain the syrup mixture over the mango, cover, and let chill in the refrigerator for 30 minutes.
3) Serve over ice cream or topped with vanilla yoghurt.