Dice all your veggies, because we're not going to pretend that isn't part of the time dedicated to getting this recipe made.
Put all the veggies and the broth into a large stock pot. Bring to a boil over medium high heat. Reduce heat to medium and boil 15-20 minutes until the potatoes are very soft when pierced with a fork.
In the mean time, melt the butter in a saucepan over medium heat. Stir in the flour and whisk for one minute while still on the heat.
Whisk in the milk and cook until the mixture lightly bubbles and is thick. Whisk the entire time, or it will burn, and this will make your soup terrible.
Once the potatoes are soft, stir in the dairy mixture. If the potatoes don't start breaking apart cook a few minutes longer.
Mix in the sour cream. Add salt and pepper to taste
Ladle into bowls. Top with chopped green onions, shredded cheddar, and bits bacon or ham.