Preheat oven to 400F/205C. In a small bowl, stir together olive oil, thyme, oregano, salt, pepper and maple syrup.
Trim and peel beets. Slice in half. Place beets on a small square of aluminum foil (2 halves on each piece) and brush with olive oil herb mixture. Seal the foil, then roast for 40-45 minutes until beets are fork tender.
Remove from oven and let them cool for 15 minutes before dicing into bite-sized pieces. Let cool while you prepare the remaining ingredients.
Whisk together the salad dressing ingredients.
Add salad greens to a bowl and toss with half of the dressing. Then add beets, walnuts, feta and pomegranate seeds, and drizzle with the remaining half of the salad dressing.