Chicken-Coconut Soup with Summer Squash and Edamame

Haven't tried this yet, but it is definitely something I want to try soon!  Maybe it will be a soup my husband likes...who knows!

3 stalks lemon grass
1 1/2 inch piece fresh ginger
3 Serrano chilis
1/2 bunch fresh cilantro
5 cups chicken stock/broth
2 14 oz can coconut milk
5 shallots, chopped
2 1/2 tablespoons fish sauce
2 yellow squash
1 lb boneless skinless chicken breast
1 1/2 tablespoons light brown sugar
1 1/2 cups frozen shelled edamame
3 limes
1 1/2 tablespoons thai red curry paste
kosher salt

1. Discard outer layers of lemon grass.  Cut off tops and discard.  Bruise with flat side of knife and thinly slice stalks.  Peel ginger, cut into 4 equal slices and crush each piece with flat side of knife.  Crush the chilis in the same manner.  Chop enough cilantro stems to equal 1/4 cup.  Pluck 1/3 cup of cilantro leaves.
2. In a large sauce pan, combine broth, 1 can coconut milk, lemon grass, ginger, chilis, cilantro stems, shallots and 1 tablespoon of fish sauce.  Bring to a boil, reduce heat to low, cover and simmer for 15 minutes.
3. Cut squash crosswise into slices 1/4 inch thick and set aside.  Cut chicken into thin slices and set aside separately.  Strain the broth throw a fine mesh sieve.  Wipe the pot clean and return the broth.  Add brown sugar and remaining can of coconut milk and bring to a boil over medium high heat.  Stir in the chicken and edamame and return to a boil.  Reduce heat to medium and simmer for 5 minutes.  Add squash and simmer 2 minutes longer.
4. Cut 1 lime into 8 wedges.  With the two remaining limes squeeze 5 tablespoons lime juice.  Whisk together lime juice, remaining 1 1/2 tablespoons fish sauce and curry paste.  Add this mixture and 2 1/2 teaspoons salt to the pot and stir well to blend.  Adjust seasonings to taste.
5. Garnish with cilantro leaves and serve with a lime wedge for squeezing.