Prep the ingredients. Wash, peel (optional), and dice the potatoes. Chop the onion and mince the garlic.
Add to crock pot. Place potatoes, onion, garlic, broth, salt, pepper, and thyme into the slow cooker.
Cook low and slow.
Cook on HIGH for 3–4 hours or
LOW for 6–8 hours, until the potatoes are very soft.
Mash for creaminess. Use a potato masher to mash some of the potatoes directly in the pot. This thickens the soup.
Add richness. Stir in butter, heavy cream, and cheddar cheese until melted and combined.
Serve warm. Ladle into bowls and top with bacon, cheese, green onions, or sour cream.