This beet and potato salad, tossed with a combo of sour cream, vinegar and sweet pickles, is slightly sweet and tangy. To make prep go faster, you can skip roasting the beets yourself and use prepackaged cooked beets instead.
Preheat oven to 400°F. Place beets on a sheet of foil; drizzle with oil, and wrap up. Place the wrapped beets on a rimmed baking sheet. Roast until fork-tender, 1 hour to 1 hour, 10 minutes. Carefully unwrap and let stand until cool enough to handle, about 10 minutes. Peel and set aside.
Meanwhile, place potatoes in a large saucepan and add cold water to cover by 2 inches. Bring to a boil over high heat. Reduce heat to medium; simmer, uncovered, until the potatoes are just fork-tender, about 12 minutes. Drain and spread on a large plate or large baking sheet; let stand until cool, at least 10 minutes.
Using paper towels, gently rub the cooled beets to remove skin. Cut the beets into thin wedges. Combine mayonnaise, sour cream, dill, vinegar, mustard, salt and pepper in a large bowl. Add the beets, potatoes, eggs, pickles and onion; stir gently to combine. Garnish with additional dill, if desired.
Refrigerate in an airtight container for up to 1 day.