Preparation Using the back of a knife, lightly smash lemongrass and ginger; cut lemongrass into 4" pieces. Bring lemongrass, ginger, lime leaves, and broth to a boil in a large saucepan. Reduce heat and simmer until flavors are melded, 8-10 minutes. Strain broth into clean saucepan; discard solids. Add chicken and return to a boil. Reduce heat, add mushrooms, and simmer, skimming occasionally, until chicken is cooked through and mushrooms are soft, 20-25 minutes. Mix in coconut milk, fish sauce, and sugar. Divide soup among bowls. Serve with chili oil, cilantro, and lime wedges.
Preparation Using the back of a knife, lightly smash lemongrass and ginger; cut lemongrass into 4" pieces. Bring lemongrass, ginger, lime leaves, and broth to a boil in a large saucepan. Reduce heat and simmer until flavors are melded, 8-10 minutes. Strain broth into clean saucepan; discard solids. Add chicken and return to a boil. Reduce heat, add mushrooms, and simmer, skimming occasionally, until chicken is cooked through and mushrooms are soft, 20-25 minutes. Mix in coconut milk, fish sauce, and sugar. Divide soup among bowls. Serve with chili oil, cilantro, and lime wedges.