Brush the mussels well under cold running water, removing the "beards". Discard open mussels. Cover the mussels and cook them in little boiling water at low heat for about 10 minutes. Shake the pot in between
Peel onions and garlic, wash parsley. Chop everything finely. Chop garlic, parsley and some sea salt in a mortar. Stir smooth with wine
Heat the oil in a pot. Brown the onions in it. Dust with flour and saffron and sauté briefly. Add garlic mixture and 1/8 l water, bring to the boil and simmer for about 5 minutes
Drain mussels, discard closed mussels. Remove meat from the shells, put shells aside if necessary. Let the mussels steep in the sauce for about 1 minute, stirring carefully. Arrange mussels and sauce in their shells. Serve with white bread and salad
Drink: cool white wine, for example Albariño from the Rías Baixas