Cauliflower Soup

Karen visited with some friends a couple weeks ago and the subject of soup came up. The friend (my sister's husband's brother's daughter-in-law in case you were wondering) said she loved Pioneer Woman's cauliflower soup. I had heard before from other sources that it was good, so it re-peaked my interest. We made the soup a couple of days ago and all who ate it could not stop loving it.

Pioneer Woman's Cauliflower Soup (slightly edited)
1 stick of butter (divided)
1/2 onion, finely diced
1 carrot, finely diced
1 stalk celery, finely diced
1-2 heads of cauliflower, roughly chopped (I used one, but two would have been good)
2 T dried parsley (you can use fresh if you have it)
2 quarts low-sodium chicken broth or stock (that's four small cans)
6 T flour
2 cups milk
1 cup half-and-half (I didn't have any, so I used 1/2 cup heavy cream and 1/2 cup more milk)
2-4 tsp salt, to taste (okay, watch it on the salt- I used 1 1/2 tsp salt and felt it was plenty salty!)
1 cup sour cream, room temperature

Melt 4 T butter (1/2 stick) in a large soup pot or dutch oven. Add onion and cook about 1 minute. Add the carrot and celery and cook a couple more minutes. Add the cauliflower and parsley, stirring to combine.
Cover and cook vegetables over very low heat for 15 minutes. After time is up, add broth, bring to a boil, then reduce heat and simmer while making roux.
In a medium saucepan, melt 4 T butter (the other 1/2 of the stick). Mix the milk and flour together, whisking to combine, then add milk mixture slowly to the butter, whisking constantly (this was new to me- I'm used to adding the flour to the butter then adding the milk while whisking, but this worked too).
When the mixture is quite thick, remove it from the heat and then add the half-and-half. Add milk mixture to the soup. Continue to simmer for 15 minutes longer.
Just before serving, add sour cream to serving bowl and then ladle in a few scoops of the soup (not sure why you can't just add the sour cream directly to the soup in the pot, but maybe there's a curdling issue, like eggs?), blending it together. Pour in the remaining soup and stir, then serve.
Like I said earlier, we all loved it (okay, Caleb didn't even try it, but that doesn't count). I served it at a dinner party last night and my guests were hoping that's all they got to eat (it wasn't). Larry said he could have eaten 16 bowls of it.