1 Tablespoon olive oil	2 large leeks (white and pale green parts only, thinly sliced (about 3 cups)
½ cup chopped peeled carrots	4½ cups chicken broth or vegetable broth
2 cups fava beans*	1 cup green beans, trimmed, cut into 1-inch pieces
2/3 cup thinly sliced fresh basil	Freshly grated Parmesan cheese (optional)

* may substitue lima beans or peas for fava beans

Bring a large pot of water to a boil over high heat. Boil the fava beans in their pods until tender but not mushy, approximately 6 minutes. Remove and discard pods. Remove the outer skin of the beans. If using lima beans or peas, put directly into soup stock, no need to boil.

Heat oil in heavy large pot over medium heat. Add leeks and carrots, saute until vegetables are tender but not brown, approximately 8 minutes. Add broth and bring to a boil. Add fava beans and 1/3 cup basil and simmer until all vegetables are very tender, approximately 7 minutes longer. Season soup with salt and pepper. Stir in 1/3 cup basil. Ladle soup into bowls. Top with grated Parmesan, if desired.