Peel 4 potatoes and cut them in small cubes. Add the potatoes to a bowl of cold water.
In a large dutch oven, saute the bacon bits until crispy. Once the bacon is cooked, remove it from the pot and leave 1 Tbsp of bacon grease.
Add butter to the pot and saute diced onion. Once the onion is translucent, add in the minced garlic.
Whisk in the flour and allow it to cook for about a minute.
Add in the milk and chicken broth. Bring the pot up to a soft boil and add the potatoes into the pot. Simmer on low for about 10 minutes or until the potatoes are fork tender. Mash the potatoes lightly with a potato masher or you can use an immersion blender for an extra creamy texture. Season the soup with salt and pepper.
Stir in the sour cream and shredded cheese, and add the cooked bacon back in. Reserve some of the bacon for toppings. Bring the soup up to a boil and turn off the heat.
Serve the soup with more sour cream, shredded cheese, green onion, and extra bacon bits.