Add the butter to your Dutch Oven (or soup pot) and melt over medium heat.
Add diced chicken and season with the Italian seasoning, salt, and pepper.
Allow to cook until chicken is no longer pink. Remove from pot and set aside.
Add the olive oil to the pot and heat over medium.
Add in the garlic, onion, potatoes, carrots, celery, and green beans.
Saute for about 5 minutes, or until veggies soften a bit.
In a small bowl, combine the cream of chicken soup, milk, sour cream, and Ranch mix.
Pour mixture into soup pot and stir to combine.
Reduce heat to low and allow mixture to simmer for about 45 minutes, or until potatoes are tender.
Add chicken into pot and stir to combine.
Serve in bowls as is, or with bread/salad! Enjoy!