Peel the potatoes and cut into even strips of chips. Bake in an oven preheated to 180° C for about 20 minutes.
In the meantime, chop the onions, garlic and soup vegetables and roughly chop the parsley. Heat the oil in a large pot and sauté the vegetables briefly. Deglaze with a dash of white wine and simmer briefly.
Add the mussels and the rest of the wine to the pot and cook, covered, for a few minutes until the mussels open. Season the finished mussels with fresh pepper.
Remove the chips from the oven and salt, remove the mussels from the broth and sprinkle with parsley. Serve together. Mayonnaise goes well with this.