Add the sugar to the Thermomix bowl. Mill for 10 seconds / speed 9.
Add the mango, yoghurt, milk and ground cardamom to the bowl. Blend for 30 seconds / speed 8.
Pour into glasses, garnish with nuts (if desired) and serve immediately.
Notes
Mango Lassi is best when served very cold, so be sure to chill all your ingredients prior to making. You can also pop the mango in the freezer for 20 minutes beforehand.