Preheat your oven to 400℉ (200℃). Spread a generous layer of kosher salt in an oven-proof baking dish. Prick holes in the potatoes with a fork and place the whole, baby potatoes in a single layer on top.
Bake in the oven for 40-50 minutes until they are fork-tender. Remove from oven and let cool completely. If you want to peel the potatoes do so as soon as they are cool enough to handle.
While the potatoes are in the oven, make the beet salad. Combine the pickled beets, apple, red onion, horseradish, pickled beet juice, parsley, mayo and lemon juice in a medium bowl, season with salt and pepper and set aside.
Chop any fresh herbs you may want to use as a topping.
With a small melon-baller or spoon, carefully scoop out a little bit of the flesh of each potato, leaving enough space to fill a small spoonful of the beet salad.
Continue filling all the potatoes, then top with a small dollop of vegan sour cream and a fresh dill sprig or chopped chives.