Begin by washing and peeling the Yukon gold potatoes, then chop them into small cubes. Cut the cauliflower into florets, and finely dice the yellow onion. Mince the garlic.

In a 6- to 8-quart slow cooker, combine the chopped potatoes, cauliflower florets, cannellini beans, diced onion, and minced garlic. Pour in the vegetable stock, add unsalted butter, and dry white wine. Sprinkle in the thyme, garlic powder, and kosher salt. Stir everything together.

Cover the slow cooker with a lid and set it to cook on low for about 8 hours.

After 8 hours, carefully remove the thyme sprig from the slow cooker. Stir in the fresh lemon juice.

Use an immersion blender to puree the soup until smooth, or mash the ingredients for a chunkier texture.

Stir in the sour cream and chopped chives, adjusting seasoning with black pepper and salt.

Ladle the soup into warm bowls, topping with black pepper, potato chips, and optional shredded cheddar.