Quarter the apples and slice out the cores and seeds. Roughly chop the apples and pop them in your blender. Trim the dry ends off the celery stick, then roughly chop it and add to the apples.
Tuck the baby spinach leaves into the blender and spoon in the tahini.
Add a few ice cubes to the blender and pour in 400ml of the maple water. Blend for a few mins till the smoothie is combined. Serve straight away.