If you like, heat olive oil in a skillet over medium-high heat and brown the chicken for 3 to 4 minutes each side until it’s nicely golden; then place chicken into the slow cooker. If you prefer, simply put the raw chicken into the slow cooker without searing.
Arrange the diced potatoes, carrots, celery, and onion evenly on the bottom of the slow cooker.
Place the seared or raw chicken pieces on top of the layered vegetables.
Combine the ranch seasoning, minced garlic, and chicken broth in a bowl, whisking until the ranch mix is dissolved.
Cut the softened cream cheese into small cubes and scatter it over the chicken and veggies.
Drizzle the ranch broth mixture evenly over everything and season with salt and pepper according to taste.
Cover the slow cooker and cook on LOW for 6 to 8 hours or HIGH for 3 to 4 hours without lifting the lid.
About 30 minutes before the cooking time is up, stir in the heavy cream to the crockpot.
Take out the chicken, shred it well with two forks, then add it back into the slow cooker and stir to blend everything together.
If you want a thicker sauce, mix 1 tablespoon cornstarch with 2 tablespoons cold water and stir into the crockpot; cook on HIGH for 15 minutes to thicken.
Sprinkle freshly chopped parsley or chives over the dish before serving and enjoy it warm over mashed potatoes, rice, or egg noodles.