Wash the cucumber. Cut off eight thin slices. Put aside for garnishing. Roughly dice the remaining cucumber. Wash sorrel and dill and pluck from the stalks. Puree cucumber, sorrel and dill with the cutting stick of the hand mixer or in a blender.
Stir in yoghurt. Season to taste with salt, pepper, sugar and Tabasco. Pour into four glasses and garnish with cucumber slices.