3: Put into a bowl, salt and pepper, then add the juice and zest of 1 lemon. Mix well, cover and refrigerate for at least 1 hour (this can also be prepared the day before).
4: Meanwhile, prepare 2 tomatoes and dice. Sprinkle with fine salt and mix.
5: Prepare 150 g button or field mushrooms, chop it and pour it into a bowl. Prepare 1 red onion, chop it finely and pour it into the bowl.
6: Thoroughly drain the fish...
7: ...and add to the bowl.
8: Shred the lettuce, chop the parsley and add to the bowl.