Take some mango (frozen or unfrozen: I used frozen) and a frozen banana. Blend in a high speed blender and what have you got? You’ve got mango and banana soft serve ice cream. There’s a recipe here that suggests 1/2 cup mango to 1 banana. I don’t think you need to be too exact (bananas come in different sizes, in any case). I also thought that some passionfruit would be a nice addition.