Peel the cucumber. Cut 2/3 of it into pieces and finely dice the rest. Wash and quarter the tomatoes. Quarter the peppers and remove the core. Peel and finely dice a quarter of each pepper and roughly dice the rest. Pure the  roughly chopped vegetables in a blender, then pass through a fine sieve. Season the soup with salt, pepper, garlic and vinegar. Cut the chilli pepper lengthways, remove the seeds and finely dice. Cut the basil leaves into fine strips. Stir the chilli cubes and basil strips into the soup with the olive oil and then pour the soup into 4 chilled plates or cups. Add a teaspoon of the finely diced vegetables to the soup and serve over crushed ice.