In a large soup pot over medium heat, melt the butter. Season the cubed chicken with salt, pepper, and Italian seasoning. Add chicken to the pot and sauté for about 5 minutes, or until nearly cooked through. Remove the chicken and set aside.

In the same pot, add the olive oil. Toss in the diced onion, carrots, celery, and green beans. Cook until vegetables have softened, about 5-7 minutes, stirring occasionally.

In a bowl, whisk together the cream of chicken soup, whole milk, sour cream, and ranch seasoning until smooth. Pour this mixture into the pot and stir until combined. Add chicken back into the pot along with the red potatoes.

Let simmer uncovered for about 25 minutes, or until potatoes and carrots are fork-tender. Stir occasionally and adjust seasoning to taste.

Season chicken and add it to the heated butter in the crockpot along with the oil, diced vegetables, and potatoes.

In a separate bowl, combine the cream of chicken soup, milk, sour cream, and ranch seasoning, then pour over the chicken and veggies.

Cover and cook on LOW for 6-8 hours, or until everything is tender and melded together.

Set your Instant Pot to 'Sauté.' Add the butter and olive oil, then toss in the onions, carrots, celery, and green beans. Cook until the onions are soft.

Add 1 cup of chicken broth to deglaze the pot, scraping any browned bits. Season chicken and add it to the pot, close the lid, and set to pressure cook for 8 minutes.

Quick-release the pressure, switch to 'Sauté.' Stir in the soup, ranch seasoning, and half of the milk and sour cream, allowing it to simmer for about 5 minutes.