cold comfort OR cauliflower potato soup

Baby, it's cold outside.
I love the winter with it's crisp white snow, cold air and lots of blankets inside.  Winter, after all, is the month of hot bread out of the oven, all day dinners in the crockpot and lots and lots of soup!  I love this Wisconsin Cauliflower Soup from one of my favorite food blogs, Butter, with a side of Bread.  I adjusted this yummy recipe just a bit by adding some potatoes to the soup.  In this soup, I find that the immersion blender is a lifesaver.  I love my immersion blender!  I didn't tell my family there was cauliflower in the soup.  They had no idea!  It really tastes just like a delicious chowder.

WISCONSIN CAULIFLOWER SOUP
adapted from Butter, With A Side of Bread

2 tablespoon butter
1 medium onion, chopped
1/4 cup all-purpose flour
1/2 teaspoon salt
2 cups milk**
1 1/2 cups water**
1 can (13 3/4 to 14 1/2 ounces) chicken broth
1 head (2 1/2 pounds) cauliflower, cut into 1-inch chunks
3 large russet potatoes, cut into 1-inch chunks
1 teaspoon Dijon mustard
1 cup sharp cheddar cheese, shredded
1 cup Pepper Jack cheese, shredded

**Can substitute 1 can {12 oz} evaporated milk and 2 cups water for the 2 cups milk and 1 1/2 cups water.

In a large saucepan, melt butter over medium heat. Add onion and cook until golden, about 10 minutes, stirring occasionally. Whisk in flour and salt. Gradually stir in milk, chicken broth, and water.  Add cauliflower and potatoes, heat to boiling over high heat. Reduce heat to low; cover and simmer until tender, about 15 minutes. In blender (with center part of blender cover removed to allow steam to escape), blend cauliflower mixture at low speed in small batches until very smooth. {Don't let this step deter you from making the soup! Blending it is really easy and so worth the extra 3 minutes. The most annoying part are the added dishes!} If you have an immersion blender, use it- it literally takes less than a minute to blend. Return cauliflower mixture to saucepan; heat over medium heat until hot, stirring occasionally. Remove saucepan from heat; stir in mustard and 1 1/2 cups cheese until melted and smooth. Serve soup with remaining cheese as a garnish.