Place the mango pieces, yogurt, sugar (as needed), ground ginger (if using), and milk into a blender.
Blend everything on high speed until you get a creamy, lump-free consistency. If the lassi seems too thick, add a little more milk gradually until you reach your desired texture.
For a colder, more refreshing drink, add a few ice cubes just before serving and blend again for a few seconds.
Pour the mango lassi into glasses and optionally garnish with crushed pistachios, saffron strands, or a sprinkle of ground cardamom. Serve immediately for the best taste!