Wash the artichokes well, then scrape off the thin outside layer with a kitchen knife. Cut the artichokes into thin slices and soak in water for 20 minutes, then drain.
Heat the olive oil in a large saucepan. Add the onion and fry for a few minutes to soften, then add the chopped bacon and fry for another couple of minutes. Next add the artichokes and pour in the stock. Bring to a gentle boil, add the salt, and simmer for 20 minutes.
While the soup is simmering, in a frying pan, heat the olive oil for the croutons and gently fry the garlic. Add the rye bread strips and sauté for about five minutes. Sprinkle with salt, then drain on kitchen towel until cooled and crispy. Just before serving, drizzle them with the truffle oil.
In another frying pan, fry the four rashers of bacon until crispy, then remove from the pan, drain on kitchen towel and chop.
Remove the soup from the heat, pour into a blender or food processor and blend to the desired consistency.
Serve the soup with the bacon and chopped parsley sprinkled on top. Finally, drizzle each soup bowl with a little extra truffle oil and serve the rye bread croutons either on top or on the side.