Whisk Dressing ingredients together until well blended. Season to taste. Set aside.
Place beets in baking pan, drizzle with the oil, and season with salt. Cover with foil. Bake about 1 hour, or until tender when pierced with a knife.
When cool enough to handle, peel the beets, cut into quarters, add the Walla Walla Sweet onions. Toss with prepared dressing. Serve on a bed of wild greens.
Grate the frozen blue cheese wedge over the salad. Season to taste.