Place the whole chicken in a large heavy-bottomed pot and cover with cold water. Bring to a gentle simmer over medium heat, skimming off any foam that rises to the surface.
While the broth begins to simmer, dice the onions and mince the garlic. Prepare the carrots and celery by slicing them into rounds.
After about 30 minutes, add the diced onions and minced garlic to the pot. Continue simmering gently, allowing the flavors to develop.
Simmer uncovered for about 1 hour, skimming foam as needed. The broth should become clear and fragrant, and the chicken will start to loosen from the bones.
Remove the chicken from the pot using a slotted spoon and set it aside to cool slightly. Strain the broth through a fine mesh strainer to remove solids, then return the clear broth to the pot.
Once cooled enough to handle, shred the chicken meat into bite-sized pieces with two forks, discarding the bones and skin.
Return the shredded chicken to the strained broth. Add the sliced carrots, celery, chopped thyme, and parsley. Bring to a gentle simmer and cook for another 20 minutes until vegetables are tender.
Taste the soup and season with salt and pepper as needed. The broth should be flavorful, and vegetables should be tender but not mushy.
Serve the hot chicken soup in bowls, garnished with extra parsley if desired. Enjoy the comforting aroma and wholesome taste.
