Put the celery, cucumber, swiss chard leaves, kale and apple in a blender and whiz until smooth. Add the ice and whiz until the ice is crushed. Add the water and whiz until comined.
A member of our Healthier Habits community told us that she loves a green smoothie but she can't drink it in the mornings. So she packs it and takes it with her during the day. We love this idea and we used a cleaned glass tomato passata bottle.