Peel cucumber, cut in half lengthwise, scrape seeds out with a spoon and coarsely chop.
Rinse celery, trim and cut into pieces. Reserve some delicate celery leaves. Drain artichoke hearts and roughly chop.
Mix cucumber, celery and artichoke in a blender with peppercorns, lime juice and crushed ice. Add some cold water if needed and season with some splashes of Tabasco and salt. To serve, pour smoothie into glasses, place some watercress in the center and garnish with lime slices with celery leaves.