How to Make It
In a medium saucepan, cover the potatoes with cold water and bring to a boil. Add salt and simmer over moderately low heat until just tender, about 30 minutes.
Meanwhile, in a small saucepan, boil the Gamay Noir over high heat until reduced to 2 tablespoons, about 7 minutes. Transfer it to a medium heatproof bowl and let cool. Whisk in the remaining ingredients.
Drain the potatoes and let cool slightly; peel while still warm and slices crosswise 1/4 inch thick. Put the potatoes in a large bowl and toss with 2/3 cup of the vinaigrette. Season with salt and pepper and serve warm or at room temperature.