Cut the beetroot into small chunks (about eight pieces per beetroot) and place into a blender. Immediately wash your hands, or the beetroot will stain!
Add the chickpeas, garlic, lemon juice, salt and oil. Pulse until smooth, adding a splash of water if necessary – some beetroots are wetter than others, and it’s easier to loosen a hummus than thicken one up again. Sprinkle over the seeds, if using.