Seperate the kohlrabi stems and leaves from the head, and wash them well. Peel the orange, slice the banana and the green apple, and put them in a blender.
Add the oils and the vinegar, then pour on the water and the ice cubes. The consistency of the smoothie can be controlled with the quantity of the water. Blend the ingredients very thoroughly so that the mix becomes nice and silky.
Enjoy your smoothie right after mixing it.
This is a truly frugal recipe as it makes use of the stems and leaves of the kohlrabi, which we normally throw away after purchase.