Ingredients

• 1 large onion, chopped (1 cup)
  
• 2 stalks celery, chopped (1 cup)
  
• 1 medium leek, thinly sliced or 3 green onions, thinly sliced
  
• 1 large clove garlic, minced
  
• 2 tablespoons butter
  
• 1 1/2 pounds sweet potatoes, peeled and cubed (about 5 cups)
  
• 4 cups reduced-sodium chicken broth
  
• 1 3 - inch cinnamon stick
  
• 1/4 teaspoon ground nutmeg
  
• 1 1/2 cups half-and-half or light cream
  
• 2 tablespoons maple syrup
  
• Sliced leeks (optional)