adapted from San Francisco Ferry Plaza Farmers’ Market Cookbook by Christopher Hirsheimer and Peggy Knickerbocker
For oven roast: Preheat oven to 375°F. Cut off beet greens, leaving 1-inch stems; leave root intact. Scrub clean with water and place in a glass baking dish. Add water to about ¼ inch, cover tightly with foil, and bake for about 45 minutes, until beets are fork-tender. When cool enough to handle, peel then slice into rounds or cut pole-topole into 8 wedges (or cut some of each).
For sous vide: Trim off the roots and greens, wash and peel the beets. Place the beets in a sous vide bag (I kept the yellow beets separate from the red by using two bags) and drizzle in a tablespoon of olive oil and a teaspoon of wine vinegar. To make a sous vide bag, use FoodSaver vacuum bags, Zip-lock freezer bags, or silicone Stasher bags—just keep in mind that the bag’s color will never be the same after you cook red beets in it. Cook to 185°, which takes about 2 hours for 2-inch beets. Remove from water bath and let cool. Refrigerate until you are ready to make the salad.
In glass measuring cup, mix shallot with vinegars, and a few pinches of salt and several twists of freshly ground black pepper, and let stand at least 5 minutes to mellow the shallot. Whisk in the olive oil.
Preheat oven to 250°F. In large frying pan, combine sugar and water over medium-high heat and cook until sugar dissolves and syrup comes to a boil. Add the walnuts, butter, a pinch or two of salt, and cook, stirring constantly, until syrup coats the nuts and almost no liquid syrup is left in the pan. Spread the nuts out on a baking sheet and put in the oven to toast for about 15 minutes. Store air tight for up to 2 weeks.
Slice beets and drizzle with a couple tablespoons of vinaigrette. Dress greens starting with a tablespoon of vinaigrette and adding more if desired. Keep extra vinaigrette refrigerated and use within a week.
Place greens on a platter, top with beets, blue cheese crumbles, and candied walnuts.