Pat chicken thighs dry with paper towels. Season with salt and black pepper.
Heat oil in a pot over medium-high heat. Sear chicken thighs until brown for about 3-4 minutes on each side. Transfer to a plate. Reserve about 2 tablespoons of grease and discard the remaining.
Add onion and cook for 4 minutes. Add garlic and cook for 1 minute.
Add broth, stirring to loosen browned bits from pan. Add carrots, celery, bay leaves, and thyme. Bring to a boil, then lower the heat to medium, simmer, covered, until the chicken is fully cooked for 20-25 minutes.
Remove the chicken from the pot and skim off the fat that rises to the top. Add ginger slices and egg noodles. Cook, uncovered, for 4-5 minutes.
Shred the chicken thighs, discard the skin, and put them back into the pot. Cook for 2 minutes or until the pasta is al dente.
If the broth is too little, you can add 1-2 cups of hot chicken broth into the soup. Adjust seasoning with salt and black pepper according to your liking.
Serve with chopped parsley.