Serves: about 41) To make the potatoes: Tie the thyme, parsley, rosemary, and bay leaf together with a piece of kitchen twine. Put the bundle in a medium saucepan along with the wine and garlic. Slice the potatoes into 0.5cm-thick rounds and add to the saucepan. Add cold water, to cover by 2.5cm, and the salt. Bring to a boil over medium-high heat. Adjust the heat to maintain a gentle simmer, and cook until the potatoes are tender but not mushy, about 5 minutes. Drain the potatoes, and discard the herb bundle.
2) Meanwhile, make the dressing. In a large bowl combine the vinegar, mustard and salt and season with pepper, to taste. Gradually whisk in the oil to make a smooth dressing.
3) Add the warm potatoes to the dressing and toss very gently to combine, taking care not to break up the potatoes. Add the celery and set aside to cool.
4) When ready to serve, carefully fold in the parsley and spring onions.