Peel the skin from the mango, then slice all the flesh from the stone. Add it to the blender. Trim the carrots and chop them into small pieces (no need to peel). Finely grate in the zest from the lime and squeeze in the juice from half. Sprinkle in the macca root powder.
Pour in a third of the carton of oat drink (save the rest for your other smoothies this week) and drop in a few ice cubes. Whizz till smooth,. Taste and squeeze in more lime juice if you think it needs it, then serve.