Preheat the oven to 400℉.

Scrub the beets and place on a large sheet of foil, sprinkle with 1 tablespoon of olive oil and fold the sides up to make a sealed pouch.

Wipe off the mushroom caps, place them on another large sheet of foil, sprinkle with 1 tablespoon of olive oil, season with salt and pepper and fold the sides up to make a sealed pouch. Place both pouches in the oven.

Bake the mushrooms for approximately 20 minutes, or until cooked through.

Bake the beets for approximately 45 minutes, until they are tender when pierced with a knife.

Meanwhile, in a bowl combine the vinegar, mustard and olive oil and set aside.

When the beets and mushrooms are fully cooked, remove from the oven. Slice the mushrooms into strips. With a knife, remove the tops of the beets, slide the skins off with your hands.

Slice the beets and toss with the warm mushrooms and cheese, cover with foil so they stay warm until you serve them.

In a salad bowl, toss together the spinach, walnuts, onion, parsley and dressing.

Divide the salad onto 4 plates and top with the beet and mushroom mixture.