1. Put all the ingedients, except the oil, pea shoots and ice cubes, into a food processor with a good pinch of salt and pepper and blitz, adding enough water to get a soupy consistency. Taste, add a little more vinegar and seasoning if necessary. Chill for up to 24 hours, or at least 2 hours.
2. To serve, divide between shallow soup bowls, float a few ice cubes in each bowl and add a scattering of pea shoots and a drizzle of oil before serving.