Chop the onion and mince the garlic, then set aside. Dice the chicken into small, bite-sized pieces.
Heat the large pot over medium heat and add the olive oil, allowing it to warm until shimmering and fragrant.
Add the chopped onion and minced garlic to the pot, sautéing until the onion turns translucent and fragrant, about 2 minutes. You should hear a gentle sizzle and see the mixture become slightly golden.
Stir in the diced chicken and cook until lightly browned on all sides, about 5 minutes. The chicken will release some juices and start to turn opaque.
Pour in the chicken broth, stirring to lift any browned bits from the bottom of the pot. Bring the mixture to a gentle simmer, watching the bubbles form slowly on the surface.
Add the chopped vegetables and fresh herbs to the broth, stirring well to combine. The vegetables should distribute evenly and start to sink slightly into the broth.
Lower the heat to maintain a gentle simmer and cook uncovered for about 15 minutes, or until the vegetables are tender and the chicken is cooked through. The broth should be clear and flavorful, with the ingredients softened but not mushy.
Taste the soup and season with salt and pepper as needed. Squeeze fresh lemon juice into the broth for brightness, stirring to incorporate.
Give the soup a final stir, ensuring all flavors meld together. The broth should be clear with a slight sheen, and the ingredients tender and colorful.
Serve the hot soup in bowls, optionally garnished with extra herbs. Enjoy the cozy, nourishing flavors with slices of crusty bread on the side.
