Sweet Potato and White Bean Soup with Sage-Walnut Pesto

I tried this recipe and was really very pleased with it!  It looks difficult, but was actually quite fast and easy.  All my boys gobbled it up and went away filled.  My only regret is that I didn't double the recipe!  It comes from Cooking Light.

Ingredients

Soup:

• Cooking spray (I used olive oil)
• 2 cups thinly sliced leek (about 2 medium)
• 3 cups fat-free, less-sodium chicken broth
• 1 cup water
• 2 cups (1/2-inch) cubed peeled sweet potato
• 4 cups chopped Swiss chard (about 1 bunch)
• 1/4 teaspoon freshly ground black pepper
• 1/8 teaspoon salt
• 1 (19-ounce) can cannellini beans, rinsed and drained
• 2 tablespoons fresh lemon juice  

Pesto:

• 1/4 cup (1 ounce) grated Asiago cheese (I used Parmesan)
• 1/4 cup chopped fresh parsley
• 2 tablespoons chopped walnuts (I thought I had the nuts but I was out.  I just skipped the nuts and the pesto was still great, but I'm sure inferior to what it would have been)
• 1 tablespoon chopped fresh sage (I used dried)
• 1 tablespoon walnut oil (I used olive oil)
• 1 garlic clove, peeled

Preparation

• To prepare the soup, heat a Dutch oven over medium heat. Coat pan with cooking spray. Add leek to pan; cook 8 minutes or until tender, stirring frequently. Stir in broth and 1 cup water; bring to a boil. Add potato; cook 10 minutes or until potato is tender. Stir in chard, pepper, salt, and beans; cook 3 minutes or until chard wilts. Remove from heat; stir in lemon juice.
• To prepare the pesto, combine cheese and remaining ingredients in a food processor; process until smooth, scraping sides of bowl occasionally. Ladle 1 cup soup into each of 6 bowls; top each serving with about 2 teaspoons pesto.