Step 1 Pour the chicken broth into a pot and bring to a gentle boil over medium heat. Reduce the heat to medium-low, add the lemongrass, chiles and fish sauce and simmer for 30 minutes. Add the rice and cook, uncovered, for at least 1 hour.
Step 2 Stir in the shredded chicken and season to taste with salt. Continue to cook until the chicken is heated through, about 15 minutes. Divide the congee among 4 to 6 large soup bowls, garnish with saw leaves and 1 wedge of lemon for each serving.