Miso Noodle Soup

1 . Stage

Set a large pot over medium-low heat. Add oil and heat for 1 minute. Add leeks and garlic; cook, stirring occasionally, while preparing chard. Remove stalks and ribs from chard; set leaves aside. Coarsely chop stalks and ribs, and add to pot. Cook, stirring occasionally, until tender, 8 to 10 minutes.

2 . Stage

Add 2 1/2 quarts water to pot. Increase heat, and bring to a boil. Add carrots, then reduce heat to simmer. Continue simmering until carrots are tender, about 10 minutes more. Meanwhile, bring a separate pot of water to a boil. Add buckwheat noodles, and cook until tender, about 3 minutes (do not cook in soup pot because they will soak up too much broth). Drain with a colander and run under cold water; set aside.

3 . Stage

Coarsely chop reserved chard leaves, and add to soup along with edamame. Cook until just wilted, then quickly increase heat and bring liquid to a boil. Remove 1 cup boiling liquid, and swirl into a bowl with miso; set aside.

4 . Stage

Add shredded chicken (if using) to pot; cook to heat through, about 2 minutes. Add noodles, and whisk miso mixture into soup. Serve immediately: Divide soup among bowls, and garnish with scallions.