Place the chicken bones and carcass on a baking sheet and roast in the oven at 200°C (390°F) for about 30 minutes until they develop a deep, smoky aroma and are nicely browned.
While the bones roast, dice the onion, carrots, and celery to prepare for sautéing.
In a large stockpot, heat oil over medium heat, then add the diced vegetables. Sauté for about 8 minutes until the vegetables soften, release their aroma, and turn slightly golden.
Add the roasted bones to the pot, along with enough water to cover everything. Bring to a gentle simmer and cook for 1.5 hours, skimming off foam as needed to keep the broth clear and flavorful.
While the broth simmers, cook the chicken breast separately in boiling water until cooked through, then shred into bite-sized pieces.
Strain the broth through a fine strainer into a clean pot, discarding the solids. Return the clear broth to the pot and bring to a gentle boil.
Add the uncooked egg noodles, shredded chicken, and fresh thyme to the boiling broth. Cook for about 10 minutes until the noodles are tender and the soup is bubbling.
Season the soup with salt and pepper to taste, then squeeze fresh lemon juice into the pot for brightness.
Ladle the hot soup into bowls, garnish with chopped parsley, and serve immediately for a comforting, smoky chicken noodle soup experience.
