Heat a heavy-bottomed pot over medium heat and add a tablespoon of olive oil. Once shimmering and fragrant, add diced onions and cook until translucent and soft, about 5 minutes, filling the kitchen with a sweet, savory aroma.
Add the minced garlic to the pot and cook for another minute until fragrant, stirring constantly to prevent burning.
Stir in diced carrots, celery, and potatoes, then cook for about 8 minutes, stirring occasionally, until the vegetables begin to soften and release their aroma.
Pour in the chicken broth and bring the mixture to a gentle simmer, watching for small bubbles and a fragrant, savory smell filling the air.
Add the shredded cooked chicken to the simmering broth, stirring gently to combine everything evenly.
Reduce heat to low and let the soup simmer gently for 20-25 minutes, stirring occasionally, until the vegetables are tender and the flavors meld beautifully.
Taste the soup and adjust the seasoning with salt and pepper as needed. Squeeze fresh lemon juice directly into the pot for a bright, lively finish.
Use a ladle to serve the hearty, steaming soup into bowls, ensuring each gets a good mix of vegetables and chicken.
Finish with a final squeeze of lemon and a sprinkle of freshly ground black pepper, then enjoy this cozy, comforting bowl of chicken vegetable soup.
