Roasted Root Vegetables Soup

A satisfying soup from a Suppers meeting last week. Whenever you can, get beets with the greens attached. Soak the leafy green - stalks included - in cold water to get rid of the grit. Drain and incorporate into recipes as we did here.

Ingredients
1 bunch red beets, greens reserved - peeled and diced into large chunks.
4 turnips, peeled and diced into large chunks
4 parsnips, scraped and cut into large chunks
Kosher salt to taste (optional)
Dried herbs to taste
Olive oil to roast the vegetables and to start the soup
A 1-inch piece of fresh ginger, grated
Beet stalks and greens, cleaned and chopped
2 1-quart (8 cups total) cartons vegetables stock
1 bag (about 12 ounces) fresh spinach
2-4 tablespoons good quality cider vinegar to taste
Salt to taste

Directions
Preheat the oven to 400F.
In a large roasting pan, combine the beets, turnips, parsnips and enough olive oil to cover lightly. Toss until all vegetables are coated with oil. It’s OK if the beets color the other vegetables. Sprinkle with optional salt and dried herbs and toss again to distribute salt and herbs evenly.
Spread vegetables in in the pan in one layer and roast for 30-35 minutes or until fork-tender. Remove from the oven.
Heat a stock pot with just enough olive oil to cover the bottom over a medium-high flame. Add beets greens and ginger. Stir to coat with olive oil and saute for about a minute. Add roasted vegetables and stock, bring to a boil and then reduce heat to a simmer.
Simmer for about 15 minutes and take off the heat. Just before serving, while the soup is hot, season with vinegar and some salt to taste. Add spinach leaves and stir until wilted. Serve immediately.