Pour cold water over the well cleaned mussels, enough to cover them, and bring to a boil. Boil just 3-4 min. until the shells open up, then clean them.
In a deep container, mix the cleaned mussels with finely chopped green onions, dill and parsley. Season the ingredients with olive oil and lemon juice, add salt if desired.
Stir the salad very well and serve cooled.