- 6 medium beets (2 1/4 lb with greens), trimmed, leaving 1 inch of stems attached
- 1 (1-lb) celery root (sometimes called celeriac)
- 2 tablespoons plus 2 teaspoons fresh lemon juice, plus additional to taste
- 2 tablespoons minced shallot
- 1/4 cup olive oil
- 3/4 teaspoon salt
- 1/2 cup chopped walnuts (2 oz), toasted and cooled
- Put oven rack in middle position and preheat oven to 425°F.
- Wrap beets tightly in foil to make 2 packages (3 beets in each) and roast until tender, about 1 1/4 hours.
- While beets roast, peel celery root with a sharp knife and cut into 1/8-inch-thick matchsticks. Whisk together lemon juice, shallot, oil, salt, and pepper to taste in a large bowl until combined well, then add celery root and toss until coated. Keep at room temperature, covered, until ready to add beets.
- Carefully unwrap beets and, when just cool enough to handle, slip off skins and remove stems. Cut beets into 1/8-inch-thick matchsticks and toss with celery root.
- Let salad stand, covered, at room temperature 1 hour. Taste salad and season with more lemon juice and salt if necessary, then toss with walnuts.