Place the potatoes in a large stockpot, cover with water and add about 3 tsp. of kosher salt. Bring the water to a boil and cook until the potatoes are tender, about 20 minutes.
In the last 3 minutes of cooking time, add in the asparagus. Drain and allow to cool slightly.
In large bowl, combine the vinegar and mustard. Slowly whisk in the olive oil. Add the potatoes and chopped herbs to the vinaigrette. Mix gently but thoroughly, and season with salt and pepper to taste.