Cook bacon in a large Dutch oven or soup pot over medium heat until crisp, then remove and set aside, leaving the fat in the pot.

Add butter and chopped onion to the pot, cooking over medium heat until tender (3-5 minutes).

Stir in minced garlic and cook for about 30 seconds until fragrant.

Sprinkle flour over the ingredients and stir until smooth, using a whisk if necessary.

Add diced potatoes, chicken broth, milk, heavy cream, salt, pepper, and ancho chili powder to the pot and stir well.

Bring the mixture to a boil, then cook until the potatoes are tender when pierced with a fork (about 10 minutes).

Reduce heat to a simmer, then carefully remove approximately half of the soup to a blender and puree until smooth, or use an immersion blender directly in the pot.

Return the pureed soup to the pot, then add the sour cream and reserved bacon pieces, stirring well.

Allow the soup to simmer for 15 minutes before serving.

Top with additional sour cream, bacon, shredded cheddar cheese, or chives as desired, and enjoy!