1. Peel the onions and chop them roughly. Clean the leek and carrot, cut the leek into rings and the carrot into slices.
  2. Divide the vegetables and the sprigs of celery over the bottom of the mussel pan.
  3. Wash the mussels under running water and place the closed mussels on top of the vegetables.
  4. Tap mussels that do not close directly against the counter. Throw away mussels that remain open and broken mussels. Put all the closed mussels in the pan.
  5. Sprinkle pepper over it and pour the wine over it.
  6. Bring the mussels to the boil with the lid on the pan. Lift the lid when the liquid boils and bring the mussels back to the boil.
  7. Repeat about three times until all mussels are open in about 8 minutes.
  8. Drain the mussels in a colander and serve them in the pan with baguette, chips, a mixed salad and various sauces.