Ginger and Sweet Potato Soup With Cilantro

Rich and smooth, this luxurious blend of sweet potatoes makes a divine soup. For extra-sharp gingery flavor, freshly grated gingerroot is added just before serving. The yogurt swirl looks pretty and is easy to do, or simply garnish each serving with a dollop of yogurt. (Adapted from Saved by Soup by Judith Barrett; William Morrow, 1999.)

• Ready In: 1 hr 20 mins
• Serves: 6

Ingredients

• 2  teaspoons olive oil
• 1  medium leek, white part only, cut in half lengthwise, rinsed well between layers and thinly sliced
• 1  medium carrot, chopped
• 2  lbs sweet potatoes or 2  lbs  yams, peeled and cubed
•  fresh ginger, peeled and finely chopped, plus 1 teaspoon grated
• 4  cups chicken broth, homemade or 4  cups reduced-sodium chicken broth, canned or 4  cups  vegetable stock
• 3⁄4 teaspoon salt
• 1⁄4 cup low-fat plain yogurt
• 2  tablespoons 1% low-fat milk
•  fresh cilantro leaves (to garnish)
•  lime wedge

Directions

1. Heat oil in a 4- to 6-quart Dutch oven or soup pot over medium-high heat. Add leek and carrot; cook, stirring often, until they begin to soften, 2 to 3 minutes. Stir in sweet potatoes (or yams) and chopped ginger. Add broth and bring to a boil. Cover, reduce heat to low and simmer until sweet potatoes are soft, about 30 minutes.
2. In batches, if necessary, transfer the soup to a blender or food processor and process until smooth. Return the soup to the pot, season with salt and reheat. Just before serving, stir in grated ginger. Whisk yogurt and milk in a small bowl until smooth. Ladle soup into bowls; drop a large dollop (or several small dollops) of thinned yogurt onto each one. Draw the tip of a knife or a toothpick through the yogurt to make decorative swirls. Garnish with cilantro and serve with lime wedges for squeezing into the soup.