- 2 pounds red beets, scrubbed, peeled, and diced medium
- 1 pound russet potatoes, peeled and diced medium
- 2 shallots, coarsely chopped
- 3 to 5 sprigs thyme
- 2 tablespoons extra-virgin olive oil
- Coarse salt and ground pepper
- 5 cups low-sodium chicken broth or water
- 1 tablespoon red-wine vinegar
- Sour cream, (optional)
- Chopped fresh parsley (optional)
- Thinly sliced scallion greens (optional)
- Preheat oven to 400 degrees. In a roasting pan or rimmed baking sheet, toss together beets, potatoes, shallots, thyme, and olive oil; season with salt and pepper. Arrange in a single layer and roast until beets and potatoes are cooked through, about 45 minutes.
- Discard thyme. Add vegetables to a medium pot, along with broth. Bring to a simmer over medium-high. With a potato masher or back of a wooden spoon, mash some vegetables until soup is thick and chunky. Stir in vinegar and season to taste with salt and pepper. To serve, top with sour cream, parsley, and scallion greens, if desired.
Transfer cooled soup to freezer bag or airtight container and freeze, up to 3 months. Thaw, and then reheat. Add garnishes just before serving.