Cauliflower Soup

This may not be the healthiest soup, but it sure is yummy!:)  It's very easy to make and so creamy.  Enjoy!

Ingredients:
-7 Tbs butter, divided
-1/2 onion, finely chopped
-2 heads cauliflower, cut into florets
-8 cups (2 quarts) chicken broth
-2 cups whole milk
-6 Tbs all-purpose flour
-1 cup half and half
-2-4 tsp salt, to taste
-1 cup sour cream
Directions:
In a large stockpot melt 3 Tbs butter.  Add onions and stir them around for 2-3 minutes, until they begin to brown (be sure to not burn them).  Add cauliflower and stir.  Reduce heat to low, cover and let simmer for 15 minutes, stirring occasionally.  Pour in broth and turn up the heat.  Bring to a boil.  Once boiling, lower the heat again and let simmer.
Meanwhile, melt remaining 4 Tbs butter in medium saucepan.  In a separate bowl, combine milk and flour.  Once butter is melted, add milk and flour mixture and whisk well.  The mixture should thicken into a white sauce.  Once thickened, whisk in half and half.  Pour this whole mixture into simmering soup.  Season with salt.  Let everything simmer 15-20 minutes. 
Just before serving, remove the soup from heat.  Add sour cream and stir until completely incorporated.  Enjoy!