Wisconsin Cauliflower Soup

Wisconsin Cauliflower Soup
(Copycat of Zupas)

2 tablespoon butter or margarine
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
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 margarine or 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 heat to boiling over high heat. Reduce heat to low; cover and simmer until cauliflower is 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

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.