How to Make It
Preheat oven to 400°F. Cook rice according to package directions. Rinse under cool water, and drain well. Transfer to a large bowl; set aside.
Meanwhile, bring 11/2 inches of water to a boil in a large pot fitted with a steamer basket. Peel beets, and place in basket. Cover and cook until still slightly firm but tender enough for a fork to slide in with ease, about 30 minutes. Remove and set aside until cool enough to handle. Cut beets into 1/2-inch pieces, and let cool completely.
Rinse leeks; cut off and discard dark green tops. Cut leeks in half lengthwise, then cut crosswise into 1/4-inch-thick slices. Toss together leeks, 1 tablespoon oil, 1/2 teaspoon salt, and 1/4 teaspoon pepper on a baking sheet. Roast in preheated oven 12 minutes. Let cool to room temperature.
Toss together rice, leeks, parsley, chives, walnuts, vinegar, remaining 3 tablespoons oil, remaining 1/2 teaspoon salt, and remaining 1/4 teaspoon pepper. Add beets, and gently toss.