Season chicken all over with Cajun seasoning. Heat oil in a large pot over medium-high heat. Add chicken and brown both sides, about 5 minutes per side. Transfer to a plate.

Add onion, celery, bell pepper, sausage, and carrots to the pot. Cook for 5 minutes until softened. Return chicken to pot and add enough water to cover by 1 inch.

Bring to a boil, then reduce to a simmer. Cook 1-2 hours until the chicken is very tender. Remove chicken and shred, discarding bones.

Add egg noodles to the pot and simmer for 8-10 minutes until al dente. Return shredded chicken to pot and heat through.

Ladle soup into bowls and garnish with green onions. Enjoy!