In a large pot or Dutch oven, cook the chopped bacon over medium heat until crispy, about 6-8 minutes. Remove the bacon with a slotted spoon and set aside on paper towels. Leave about 2 tablespoons of bacon fat in the pot.

Add the diced onion and celery to the pot with the bacon fat. Cook until softened, about 5-7 minutes. Add the minced garlic and cook for another minute until fragrant.

Add the cubed potatoes and chicken broth to the pot. Bring to a boil, then reduce heat and simmer until the potatoes are tender, about 15-20 minutes.

In a small bowl, whisk the flour with a few tablespoons of the hot soup liquid to create a slurry. Stir this back into the pot to help thicken the soup. Using a potato masher or immersion blender, partially mash some of the potatoes to create a thicker consistency while leaving some chunks for texture.

Reduce heat to low and stir in the heavy cream, sour cream, and dried thyme. Gradually add the shredded cheddar cheese, stirring until melted and smooth. Season with salt and black pepper to taste.

Ladle the soup into bowls and top with the reserved crispy bacon, chopped green onions, and extra shredded cheese. Serve immediately while hot.