In a small bowl, whisk together the olive oil, 1 tablespoon white wine vinegar, the Dijon mustard, sea salt, and black pepper.
Place the potatoes in a large pot and cover with cold water by about 2 inches. Bring to a boil over high heat, and add 1 tablespoon of kosher salt.
Cook until the potatoes are tender, about 15-20 minutes. Drain well.
While still warm, cut the potatoes in half and place them in a large mixing bowl. Sprinkle with 2 tablespoons of white wine vinegar and let cool.
Pour the dressing over the cooled potatoes. Add the onions, garlic, minced dill, chives, and parsley. Toss gently to combine.
Adjust seasoning with more salt and pepper if needed. Serve warm, at room temperature, or chilled.