Stir the mustard, honey, chopped garlic clove and olive oil until smooth. Remove the bowels from the prawns, wash them, pat dry with a kitchen towel and add to the marinade. Let it steep in the refrigerator for at least 30 minutes.
For the soup:
Sear the vegetables (potatoes, sweet potatoes, carrots, celery, garlic, onions) vigorously in olive oil, add the vegetable stock after a few minutes and simmer for about 25 minutes until the vegetables are soft. Crumble the dried chilli pepper and stir into the soup with the other spices and coconut milk. Puree the soup (if you don`t like soups that are too thick, you can add a little more vegetable stock) and season with salt and pepper.
Just before serving, put the prawns on wooden skewers, sprinkle with sea salt and pepper and fry on both sides in hot olive oil until they are pink.
Serve the soup with a dollop of crème fraîche, freshly ground pepper and freshly chopped parsley. Serve the prawns either in the soup or as a skewer on a separate plate.