In a large crock pot, combine the diced potatoes, chopped onion, and minced garlic.

Pour in the vegetable broth, and add the dried thyme, salt, and black pepper.

Cover and cook on low for 6-8 hours or on high for 3-4 hours, until the potatoes are tender.

Once cooked, use a potato masher or immersion blender to blend the soup to your desired creaminess.

Stir in the heavy cream and mix well. Allow to heat through for an additional 10-15 minutes.

Serve hot, topped with shredded cheddar cheese and chopped green onions if desired.