Place bacon in a large, deep skillet. Cook over medium heat until browned. Reserve 2 tablespoons of bacon grease. Drain off the rest of the bacon grease.
Crumble the bacon and set aside.
In a stock pot or Dutch oven, melt the butter and bacon grease over medium heat.
Saute the onion and minced garlic in the melted butter until the onion becomes translucent.
With the burner on low heat, whisk in flour until smooth.
Gradually stir in milk and then the chicken stock, whisking constantly until thickened.
Stir in potatoes. Use a potato masher to mash the potatoes 3-4 times just to break them up a bit.
Increase the stove temperature slightly to bring to a boil, stirring frequently.
Reduce heat and simmer 10 minutes.
Mix in the sour cream, salt, and pepper.
Mix in 1 cup of cheddar cheese and ¾ of the bacon (reserve the remaining cheese and bacon for topping).
Continue cooking, stirring frequently, until cheese is melted.
Garnish the soup with remaining cheddar cheese, bacon and green onion when serving.
The calories shown are based on the recipe making 12 cups of soup, with 1 serving being 1 cup. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**