Add the potatoes to a large pot and cover with 1 1/2 inches of water. Season water with salt.
Bring the water to a boil, and then reduce to a simmer (boiling the potatoes can cause them to hit one another and split). Cook the potatoes for 15 to 20 minutes or until easily pierced with a fork.
Meanwhile, add cold water to a medium bowl filled with ice. Drain the potatoes and then place them in the ice water.
Chop the cooked potatoes into bite-size chunks, and then add to a large bowl. Drizzle the vinegar over the potatoes and lightly season with salt.
While the potatoes cook, add the onions to a small bowl and cover with cold water. Soak for 10 minutes, then rinse. This step helps give the raw onions a milder taste.
Combine the Greek yogurt, mayonnaise, mustard and honey in a small bowl until smooth and creamy.
Add the onions, celery, dill and yogurt mixture to the potatoes in the bowl. Gently mix to combine, being careful not to break apart or mash the potatoes too much.
Season with salt and pepper to taste. If there’s time, refrigerate salad at least 30 minutes before serving.