Thinly slice the celery, fennel and leek.
Heat the oil and gently sauté the caraway seeds, celery and leek for about 8 minutes.
Remove the brown, tough outer leaves of the chicory and chop the rest.
When the veggies are soft, add the chicory to the pan and pour over the stock. Bring to the boil, and cook for 5 minutes.
Add the parsley then blend the soup with a stick-blender until smooth and silky. Taste. Season with salt and pepper.
Cut the white fish into bite sized chunks and add to the soup together with the mixed seafood. Put the lid on and cook for 5 minutes over medium heat.
Turn off the heat and rest for a couple of minutes (with the lid on). Meanwhile chop the parsley.
Stir through the parsley and vinegar, then serve warm.