1 tablespoon canola oil
2 onions, chopped
2 large carrots, peeled and chopped
2 medium potatoes, cut into 1-inch cubes
1 cup dry sherry
8 cups chicken or vegetable broth
6 cups cubed fresh pumpkin or butternut squash (3 pounds)
1 cinnamon stick
1 bay leaf
½ teaspoon ground nutmeg
½ cup nonfat plain yogurt
¼ cup chopped pistachios
Salt & freshly ground black pepper to taste

In an 8-quart soup pot, heat oil over medium heat. Add onions, carrots and potatoes. Cook, stirring occasionally until tender not not browned, 10 to 15 minutes. If necessary, add a tablespoon or two of water to prevent scorching. Add sherry and cook until liquid evaporates, 3 to 5 minutes. Add broth, pumpkin or squash, cinnamon stick, bay leaf and thyme. Bring to a boil, reduce heat and simmer, uncovered, until vegetables are tender, 35 to 45 minutes.

Remove bay leaf and cinnamon stick. In a blender or food processor, puree vegetable mixture in 4 batches. Return to pot and warm over low heat. Add nutmeg and season with salt and pepper. Ladle soup into warmed bowls; garnish with a swirl of yogurt and sprinkling of pistachios. Soup keeps well in the refrigerator up to two days.