Add chicken thighs to a stockpot. Cover with cold water. Bring to a boil, then cover and reduce heat to low.
While broth simmers, heat olive oil in a separate pot over medium heat. Add onions, cook until translucent. Add carrots and celery, cook for about 10 minutes.
Stir in minced garlic, dried herbs, salt, and pepper; cook 2 more minutes.
Strain the broth into the pot with the vegetables, set chicken aside. Add bay leaf.
Add lemon juice to the pot and bring to a boil. Reduce heat and simmer for 30 minutes. Adjust salt and pepper as needed.
Shred the cooked chicken. Add shredded chicken back to the pot. Garnish with fresh parsley before serving.