Roughly slice the bananas and freeze them for a couple of hours.
Blitz the pistachios in a blender to a fine crumb.
Once frozen, remove the bananas from freezer and add them to a blender.
Scoop out the creamy part from the top of the tin of coconut milk (save the watery part to add to your smoothies) and add this to the blender along with the pistachio crumbs and maple syrup (adding more or less for your desired sweetness!).
Either consume straight away or place in a bowl in the freezer until ready to eat (remove 10 minutes or so before you’re ready to dish it up).