Preheat the oven to 400 degrees F. Place the beets in a roasting pan and drizzle with olive oil (not extra-virgin olive oil because it will smoke) and sprinkle with salt and pepper. Cover the pan with foil and roast until the beets are soft, about 1 hour.
Let the beets cool to room temperature. Turn the oven temperature down to 350 degrees F. Reserve the beet juice from the roasting pan, and then peel and dice the beets into small cubes, about 1 centimeter. Place the walnuts on a baking sheet and toast in the oven for about 15 minutes.
For the walnut vinaigrette: Whisk together the walnut oil, red wine vinegar, honey, balsamic vinegar and shallots in a stainless steel bowl. Whisk in 1/2 cup water and the reserved beet juice. Stir in salt and pepper to taste.
Put the mixed greens into a large stainless steel bowl and add the beets, walnuts, feta and pears. Pour in 1 ladle per serving of vinaigrette and toss together.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.