1 Skin, bone and flake the salmon and put in a large mixing bowl. Mix the cheese and sour cream together, combine with the salmon and add the gherkins.
2 Dissolve the gelatine following the packet instructions and blend into the salmon mixture. Add the remaining ingredients and mix well. Pour into wetted moulds and refrigerate for at least two hours, or until set.
3 For the Sauce: Peel and de-seed the cucumber and chop finely. Mix with all ingredients except the cream and leave for 30 minutes, strain off the liquid and mix with the cream. Unmould the mousse and serve with the sauce.