Peel the mango, remove the pulp from the stone, cut about half of it into small cubes and set aside. Peel the banana, cut into pieces and finely puree together with buttermilk, vanilla sugar and lemon juice in a blender.
Pour the banana milk into two deep plates or dessert bowls, add the mango pieces and enjoy.
The cold bowl tastes best when the bananas are cold too. So you can put them in the fridge beforehand.
The cold bowl is also tasty with (peeled) peaches and apricots.