Dissolve the vegetable stock in 1/2 liter of boiling water and allow to cool. Wash and clean the cucumber. Put a piece about 6cm aside. Peel the remaining cucumber and cut into pieces. Wash the dill and pluck from the stalks. Put something aside for garnish. Add the cucumber and dill to the vegetable stock, puree with the lemon juice and 75g creme-fraiche and season with salt, pepper and nutmeg. Chill the cucumber soup for at least 30 minutes. Cut the rest of the cucumber into small cubes. Arrange the soup in bowls and put a dollop of creme-fraiche on top of each. Garnish with the cucumber pieces and a slice of salmon and remaining dill.