Prep the vegetables. Add potatoes, carrots, and onion to the slow cooker. Season with a pinch of salt and pepper. Drizzle with olive oil and toss so they’re lightly coated.
Mix the ranch sauce. In a bowl, whisk together chicken broth, ranch seasoning, garlic powder, onion powder, and smoked paprika.
Stir in the cream cheese and sour cream. It won’t be perfectly smooth yet, and that’s okay—it will melt as it cooks.
Season the chicken. Pat chicken dry and season both sides with a little salt and pepper. Nestle the chicken on top of the vegetables in the slow cooker.
Pour and cover. Pour the ranch sauce over the chicken and veggies.
Cover with the lid.
Cook low and slow. Cook on Low for 5–6 hours or on High for 2.5–3.5 hours, until the chicken is fork-tender and the potatoes are soft.
Add green beans. In the last 30 minutes of cooking, stir in the green beans so they stay crisp-tender.
Finish and adjust. Stir the sauce to fully melt and combine the cream cheese. Taste and adjust seasoning with salt and pepper. If the sauce is too thick, thin with a splash of warm chicken broth or milk.
If it’s too thin, uncover and cook on High for 15 minutes to reduce.
Serve. Spoon chicken and vegetables into bowls, top with chopped parsley or chives, and serve warm.