Bring a large pot of salted water to a rolling boil. Add the scrubbed and quartered new potatoes and cook for about 15 minutes, or until fork-tender.

In a mixing bowl, whisk together the finely chopped red onion, fresh parsley, fresh dill, apple cider vinegar, olive oil, stone ground mustard, sugar, salt, and black pepper until well combined.

Once the potatoes are tender, drain them in a colander and let them sit to evaporate excess moisture.

Transfer the hot potatoes back into the pot, pour the dressing over, and toss gently until the potatoes are well-coated.

Let the salad sit for a couple of minutes, then serve warm.