Step 1

Preheat oven to 425°F.

Step 2

Toss the parsnips, shallot and garlic with the oil on a large, rimmed baking sheet. Spread the vegetables out in a single layer. Roast until the parsnips are tender and light brown in spots, about 20-25 minutes.

Step 3

Scrape the vegetables and any juices into a blender or food processor. Add the sour cream, lemon juice and ½ cup hot water. Puree on high until smooth, about 1 minute. Add more hot water as needed to loosen the sauce. Season with salt and pepper if needed.