Mix all the ingredients for the soup in a large bowl. Ladle batches of the mixture into a blender and purée until smooth. Pour the soup into a large clean bowl, cover and chill for 2 hours.
Prepare the accompaniments towards the end of the chilling time. Deseed and cut the red capsicum into small cubes, thinly slice the spring onions and cut the cucumber into small cubes. Cut the toasted bread into small cubes to make croutons. Place each vegetable and the croutons in separate small serving dishes.
Ladle the soup into bowls. Serve at once, offering the accompaniments and salt and pepper so that they can be added to taste as the soup is eaten.