- 2 tablespoons (1/4 stick) butter
- 2 small celery stalks, stalks and leaves chopped separately
- 1 medium leek, sliced (white and pale green parts only)
- 1 large garlic clove, chopped
- 1 1/2 pounds red-skinned sweet potatoes (yams), peeled, cut into 1-inch pieces (about 5 cups)
- 4 cups chicken stock or canned low-salt chicken broth
- 1/4 teaspoon ground nutmeg
- 2 tablespoons pure maple syrup
Melt butter in heavy large pot over medium-high heat. Add onion and sauté 5 minutes. Add chopped celery stalks and leek and sauté until onion is translucent, about 5 minutes. Add garlic and sauté 2 minutes. Add potatoes, chicken stock, cinnamon, and nutmeg; bring to boil. Reduce heat and simmer uncovered until potatoes are tender, about 20 minutes.
Remove cinnamon stick and discard. Working in batches, puree soup in blender until smooth. Return to pot. Add half and half and maple syrup and stir over medium-low heat to heat through. Season soup to taste with salt and pepper. DO AHEAD Can be prepared 1 day ahead. Cool soup slightly. Cover and refrigerate soup and celery leaves separately. Bring soup to simmer before continuing. Ladle into bowls. Sprinkle with celery leaves.