Scrub and coarsely grate the carrots. Peel and chop the bananas. Grate the turmeric (you may want to grate it onto a plate as it stains). Zest the orange. Slice off the white pith. Cut the orange in half and flick out any pips.
Pop the grated carrot, banana chunks, turmeric and orange zest and flesh in to the blender. Add a tiny pinch of cayenne (it’s VERY hot). Add a large cupful of ice. Blend till smooth. Trickle in water to reach your desired consistency.