Heat the large pot over medium heat and add the olive oil. Once shimmering, place the chicken thighs in the pot and sear for about 5 minutes per side until golden brown. Use a meat thermometer to check that the internal temperature reaches 165°F (74°C).
Add diced onions and sliced carrots to the pot around the chicken. Cook for about 5 minutes, stirring occasionally, until the vegetables soften and release their aroma.
Pour in the chicken broth, bringing the mixture to a gentle simmer. Cover the pot and let everything cook on low heat for about 45 minutes, allowing the flavors to meld and the chicken to become tender.
Carefully remove the chicken thighs from the pot and shred the meat with two forks. Return the shredded chicken to the soup.
Squeeze fresh lemon juice into the soup and stir in chopped parsley and dried thyme. Season with salt and pepper to taste, adjusting as needed.
Let the soup rest for about 10 minutes to allow the flavors to develop further. Give it a gentle stir before serving hot, garnished with extra herbs if desired.