Cook bacon in a large 5-6 quart pot over medium heat. Cook and stir until crisped. Remove bacon and place onto a paper towel lined plate to drain. Add onion, carrot and celery to hot oil, stirring and cooking until fork tender, about 5-8 minutes. Whisk in flour, stirring until well combined, letting cook for a few minutes. Stir in chicken broth and half of the bacon, stirring to combine. Add diced potatoes, salt, pepper and garlic salt, stirring to combine. Let potatoes cook until fork tender, about 15 minutes. With the back of a fork, mash most of the potatoes and vegetables, this creates a thick, creamy soup base. Stir in cream and let warm on low-medium heat for 15 minutes. Reduce heat to simmer until ready to serve. Serve each cup of soup topped with shredded cheese, remaining bacon crumbles, and chives or green onion.