Onion cut into thin quarter rings. Chop greens. Tomatoes cut into halves.

Combine the mustard, lemon juice, olive oil, wine, salt, pepper and mix. Add the onion to the marinade and leave for 10 minutes.

Unfreeze the shrimps and put them for 2-3 minutes into boiling water.

Of the mussels drain the marinade.

Remove the tuna from the oil and mash with a fork.

Mix seafood, tuna and onion with the marinade. Add the greens and stir.

Place seafood salad on a dish, decorate with tomatoes, sprig of greens and serve.