1. In a large pot or Dutch oven, cook chopped bacon over medium heat until crispy. Remove with a slotted spoon and set aside. Leave 2 tablespoons of bacon fat in the pot.

2. Add butter to the pot. Stir in chopped onion and cook until translucent, about 5 minutes. Add garlic and cook for another 30 seconds.

3. Sprinkle flour over the onion mixture and stir for 1 minute. Gradually pour in the chicken broth while whisking until smooth.

4. Add diced potatoes and bring the mixture to a boil. Reduce heat to a simmer and cook uncovered for 15 to 20 minutes or until potatoes are fork-tender.

5. Use a potato masher to mash some of the potatoes for a thicker texture. Optionally, use an immersion blender for a smoother soup.

6. Stir in the heavy cream or milk. Add shredded cheddar and mix until fully melted. Season with salt and pepper to taste.

7. Serve hot in bowls and top with crispy bacon, extra cheddar, and chopped chives.