Place bacon pieces in a stock pot over medium heat and cook until crispy. Move the bacon to a clean plate and set aside, leaving 2 tablespoons of fat in the pot.

Add the butter to the bacon fat and melt it. Next, add the chopped onion and cook over medium heat until the onions are soft, about 4 to 5 minutes. Add minced garlic and cook for 30 seconds.

Add the diced potatoes to the pot along with chicken stock, salt, pepper, thyme, and smoked paprika. Stir well and bring to a boil. Cook until the potatoes are tender when pierced with a fork, about 10 to 12 minutes.

Remove the pot from heat. Use an immersion blender to puree the soup until it's chunky, blending for about 30 to 45 seconds.

Stir in the heavy cream and sour cream. Allow the soup to simmer on low heat for 15 minutes. Before serving, stir in the reserved bacon.

Serve this comforting potato soup hot in bowls with optional toppings like shredded cheddar cheese or green onions.