Wash potatoes and add to a large pot of cold water. Bring to a boil and cook until fork-tender but not mushy.
Drain and let cool slightly—potatoes should still be warm. Peel and slice into ¼-inch rounds.
Add sliced potatoes to a large mixing bowl. Season with salt, pepper, Accent, and onion powder. Toss gently.
Finely chop the white onion and mix it into the potatoes. Adjust seasoning to taste.
In a separate bowl, whisk about ¾ of the mayo jar until smooth. Slowly add milk, whisking until the dressing is creamy and pourable (not watery).
Pour half the dressing over the potatoes and mix gently. Add the rest and mix again, coating all slices.
Cover and refrigerate overnight.
Before serving, give it a gentle stir and sprinkle with paprika for garnish.
