If desired, warm 2 tbsp olive oil in a large skillet over medium-high heat and brown the chicken for 3 to 4 minutes per side until golden, then move it to the slow cooker.
Place the diced potatoes, carrots, celery, and onion evenly at the base of the slow cooker.
Lay the seared or raw chicken pieces atop the vegetables.
Mix the dry ranch seasoning, minced garlic, and chicken broth in a bowl until smooth and pour this over the chicken and veggies.
Cut the softened cream cheese into cubes and add it on top. Season with salt and pepper.
Cover and cook on low for 6 to 8 hours or on high for 3 to 4 hours without removing the lid.
Stir in heavy cream during the final 30 minutes of cooking.
Take out the chicken, shred it with two forks, then return it to the slow cooker and stir well.
If the sauce is too thin, combine 1 tbsp cornstarch with 2 tbsp cold water, stir in, and cook on high for another 15 minutes.
Garnish with parsley or chives and serve warm over mashed potatoes, rice, or egg noodles.
