How to Make It
Combine chicken, broth, bay leaves, garlic, 2 teaspoons salt, and 8 cups water in a large pot. Bring to a boil, then reduce to a simmer. Cover and simmer until chicken is cooked through, 35 to 40 minutes. Remove from heat. Transfer chicken to a cutting board. Strain stock into a large bowl and discard solids. Remove meat from chicken and shred; discard skin and bones.
Wipe the pot clean. Melt butter over medium-high. Add carrots, celery, onion, and thyme and cook, stirring occasionally, until softened, about 8 minutes. Add reserved stock and remaining 4 teaspoons salt; bring to a boil, stirring occasionally. Add noodles; cook according to package directions. Remove from heat and stir in shredded chicken, parsley, and pepper.