Finely chop a third of one of the cucumbers and set aside for when you’re ready to serve later. Roughly chop the remaining cucumbers and tip into a blender or food processor along with the yogurt and the lime juice from one lime. Add the tarragon, most of the mint leaves and most of the chives. Blitz until the mixture is smooth. Taste the soup and add some or all of the lime juice from the second lime if you want more acidity.

Pour the soup into bowls or small cups, scatter over the finely chopped cucumber, remaining mint leaves and the rest of the chives. Drizzle with a little rapeseed oil just before serving.