My whole family loves soups especially in the winter months. I end up having to make a lot because their is always some extra people showing up when I cook. My 4 year old son is a very picky eater but when it comes to this soup he always has multiple servings. If he likes it, I know everyone will too. A Keeper for your recipe box.
In a large skillet cook bacon until crispy. Drain on a paper towel, crumble then set aside. Reserve the pan drippings. Cook onion in bacon drippings over medium high heat for 6 minutes until tender.
In a large 6 quart soup pot mix onion, broth and potatoes. Heat to a boiling then reduce heat to a simmer cooking about 10 minutes or until potatoes are tender.
In the same skillet as the bacon was cooked in, melt butter over low heat. Stir in flour with a whisk until smooth. Cook and stir 1 additional minute. Gradually stir in 2 cups of the milk. Pour the milk mixture into the potato mixture. Add remaining 2 cups of milk, salt and pepper. Cook over medium heat stirring constantly with a whisk until mixture is thick and bubbly.
Stir in half of the bacon, sour cream, 2 cups of the cheese and half of the green onions. Cook until heated and the cheese is melted. Evenly top each individual servings with remaining bacon, cheese and green onions. Serve with hot buttered rolls or crackers.