Lemongrass Mushroom Sweet Potato Chicken Soup

I’ve been experimenting a bit lately with soup, with the basic approach derived from a thom ka gai recipe I got out of Cook’s Illustrated. I’ve most made them pretty spicy, with garlic and curry paste and other fairly strong flavors. For this one, I wanted to bring out a strong lemongrass flavor, so I kept competing flavors to a minimum, the main thing being shallots, which I thought would be a nice complement. The soups I’ve been doing have also been mainly a broth with a little bit of stuff in it (mushrooms, typically). I wanted this one to be more chunky. I had originally planned to add some rice or quinoa as well, but I misjudged the amount of liquid and decided that if I’d added those, it would barely have been soup any more. next time.

Ingredients
3 c low-sodium chicken stock
1 c water
15-20 medium white button and/or crimini mushrooms, stemmed, halved, and sliced
2 sweet potatoes, peeled, quartered, and sliced
2 strips bacon
a bit of tofu, cut in 1cm cubes
2 stalks lemongrass, diced
2-3 shallots, diced
2 chicken breasts, bone in and skin on
2 tbsp sugar
1 tbsp red wine vinegar
olive oil

Directions
heat the oven to 450 and bake the chicken on a roasting rack until just done (a little underdone is okay, since it will go into the soup). meanwhile, fry the bacon in a large pot. remove it, dice it, put it aside for later, and add more oil to the grease if needed. sautee the lemongrass and shallots for a few minutes, until they smell nice and flavorful. add the chicken stock and water and bring to a simmer on high. cover, turn to low, and simmer for about ten minutes. strain the soup, rinse the pot, and return the liquid to the heat. turn up to high, add the sugar, and stir until hot. add the mushrooms, sweet potatoes, tofu, and bacon. cover and let simmer on low until the sweet potatoes are soft, probably 20 minutes. meanwhile, when the chicken’s done, remove the skin, shred the meat, and add it to the simmering soup (probably one full breast and half of the other will be enough chicken). serve the soup with bread, kosher salt, freshly ground black pepper, and ground toasted quinoa or nuts.
Verdict
success! I was pretty happy with the result. The lemongrass flavor was very strong. The soup was full of stuff, all of it pretty healthy (be careful when buying low sodium chicken stock; some of it is “lesser sodium” which still has an unbelievable amount of sodium). It was flavorful and filling, and with some bread and cheese made for a satisfying meal. I’d like to try a similar thing but with brown rice or quinoa in the soup — I’ll probably make a big pot at some point. I’d also like to get a clearer, lighter broth, but I’m not sure if using proportionally more water will make it too bland.
Update: the next day, the lemongrass flavor was a lot less noticeable and the chicken was sort of chewy instead of tender. not sure what to do about that. maybe only add the chicken for serving, and save the soup without it, adding it in after reheating. not sure about the disappearing lemongrass.