Tart goat cheese gradually melts onto warm vinaigrette-coveredpotatoes to create a creamy coating.
Cover potatoes with water in a medium saucepan; season with salt, and bring to a boil. Reduce heat, and simmer until tender, 10 to 12 minutes. Drain, reserving 1 tablespoon cookingliquid. Let potatoes cool for 5 minutes.
Whisk together vinegar, mustard, and reserved cooking liquid. Add oil in a slow, steady stream, whisking constantly until emulsified.
Transfer potatoes to a bowl, and drizzle with vinaigrette. Gently stir in goat cheese, celery, shallot, and parsley. Season with salt and pepper.