Roasted Sweet Potato Soup

6 large sweet potatoes, chopped into 1" pieces
3 carrots, chopped
1 onion, chopped
2 cloves garlic, minced
4 stalks celery, chopped
4 cups vegetable stock
water
Extra-Virgin Olive Oil
2 tsp coarse salt
1 tsp black pepper
2 tsp dried oregano
2 tsp cinnamon
1/4 tsp allspice

Preheat oven to 425.  Place sweet potatoes on a large sheet tray. Drizzle with olive oil and sprinkle with 2 tsp salt, pepper, and oregano. Toss with fingers to combine. Divide vegetables onto two trays, so they are in a single layer.  (Vegetables should be in a single layer on the pan). Roast 20-30 minutes, or until vegetables are golden brown and very tender.

In a large pot over medium heat, add 2 tablespoons olive oil.  Add onions, carrots, celery, garlic, a sprinkle of salt and pepper, cinnamon, and allspice. Cook 10 minutes, until onions are soft.  Stir frequently.  Add cooked vegetables to pot along with enough vegetable broth to just cover vegetables. Put lid on pan and bring to a boil. Turn heat down and simmer, with lid on, 15-20 minutes. Add water as necessary so soup isn't too thick.  Remove from heat. Use a hand-held immersion blender (or food processor) to puree soup, again adding water as necessary to thin soup out. Add salt and pepper to taste.