Put the shrimps in a bowl and pour aquavit over them. Defrost at room temperature. Meanwhile peel onion and cut into rings. Drain the mussels on a sieve, catching the mussel juice.
Cut the cheese into cubes. For the marinade mix 4 tablespoons of mussel juice, oil and lemon juice and season with salt, pepper and caraway. Mix all the salad ingredients with the marinade and leave to marinate for about 15 minutes.
Arrange cocktail and salad leaves and garnish with chive blossoms as desired and serve.