Place the potatoes in a large pot and cover with cold water.
Bring to a simmer over medium heat and cook until potatoes can be pierced easily with a fork, about 20 - 30 minutes.
Meanwhile, mix together the fresh herbs, shallot, lemon juice, seasonings, Worcestershire sauce, sour cream, mayo and buttermilk.
Place the pot of cooked potatoes in the sink and run cold water in the pot until the potatoes are completely cool to the touch.
Transfer potatoes to a paper towel lined cutting board and allow to dry for about 20 minutes.
Cut the potatoes into bite-sized cubes and place in a large bowl.
Pour the dressing over the potatoes and mix well. Allow to chill for at least one hour before serving.