Defrost the calamari and octopus, wash briefly. Cook the calamari in boiling salted water for 20 minutes. Cook octopus in boiling salted water for 20 to 30 minutes until soft. Meanwhile wash the mussels, throw away all opened ones.
Boil closed mussels in little boiling water (about 1/8 litre) for about five minutes until all shells have opened (throw away the mussels that now remain closed).
Remove the mussel meat from the shell. For the scampi, boil 1/2 litre water with caraway, bay leaf, salt and peeled, halved onion. Cook the scampi in the hot stock for four minutes.
Put the octopus and calamari in a sieve and let them cool down. Meanwhile clean and wash the celery and carrots. Cut celery into thin slices and carrots into fine sticks. Wash parsley, dab dry and cut into fine strips, except for something to garnish.
Peel and chop the garlic. Cut octopus into small pieces, calamari into rings. Put the prepared salad ingredients in a bowl and mix loosely. For the vinaigrette, mix lemon juice, salt, pepper, garlic and chopped parsley.
Finally, beat the oil underneath. Pour evenly over the salad. Mix and cover and leave to stand for at least an hour. Garnish with parsley and, if desired, with the cooked scampi in the bowl.