Place bacon in a Dutch oven and cook until crispy. Remove bacon and place on a plate lined with a paper towel. When the bacon cools off, crumble it and set aside.
Return the bacon grease to the Dutch oven over medium heat and add in the butter. When it melts add in the onion, celery, and garlic. Saute until the onion is translucent.
Sprinkle the flour over the top of the veggies and stir to coat. Pour in the stock, and simmer for about 10 minutes or until the celery is your desired tenderness.