Grease the inside of a 6-quart crock pot with cooking spray or butter.
In a large bowl, whisk together cream of mushroom soup, milk, sour cream, thyme, salt, pepper, and paprika.
Layer ⅓ of the sliced potatoes in the bottom of the crock pot.
Top with ⅓ of the diced ham, ⅓ of the chopped onion, and ⅓ of the minced garlic.
Pour ⅓ of the sauce mixture over the layers.
Repeat the layering process two more times with the remaining ingredients.
Sprinkle shredded cheddar cheese over the top.
Cover and cook on LOW for 7-8 hours, until potatoes are tender.
Let stand for 15 minutes before serving to allow the sauce to thicken slightly.
Garnish with fresh parsley before serving, if desired.
