Chop the onion and mince the garlic; peel and slice the carrots and bell pepper; prepare the shredded chicken if not already cooked.
Place the large pot over medium heat, add a little oil, and sauté the chopped onion until it becomes translucent and fragrant, about 5 minutes.
Add the minced garlic, grated ginger, and bruised lemongrass stalks to the pot. Cook for about 2 minutes until the mixture is aromatic and fragrant.
Toss in the sliced carrots and bell peppers, stirring occasionally, and cook until they start to soften, approximately 8 minutes.
Pour in the chicken broth and bring the mixture to a gentle simmer, skimming off any foam that appears on the surface.
Stir in the shredded cooked chicken and squeeze in the lemon juice, then season with salt and pepper to taste. Let the soup simmer uncovered for 20 minutes, stirring occasionally.
Remove the lemongrass stalks from the pot before serving to prevent overpowering flavor.
Taste the soup and adjust seasoning with more lemon juice, salt, or pepper if needed. Let it rest for a few minutes to deepen the flavors.
Serve the hot, fragrant soup in bowls, garnished with fresh herbs if desired. Enjoy the bright, comforting flavors with each spoonful!
