Wisconsin Cauliflower Soup

I don't know if any of you have been to Zupa's but I LOVE LOVE LOVE their cauliflower soup. We had some cauliflower that was within days of going bad so I did some searching and tried out a recipe that I think comes "kind of" close. They probably use real Wisconsin cheese but I just used sharp chedder.

2 T butter
1 medium onion, chopped (I used a white onion because I felt the flavor of a yellow onion would be too strong)
1/4 c flour
1/2 t salt
2 c milk
1 can (14.5 oz) chicken broth
1 head cauliflower, cut into 1 inch chunks
1 t dijon mustard
2 c shredded sharp cheddar cheese

1) In a 4 quart saucepan, melt butter. Add onion and cook until golden (about 10 minutes) stirring occasionally. Stir in flour and salt; cook 2 minutes stirring frequently.

2) Gradually stir in chicken broth, milk, and 1 1/2 c water (add the broth first so you don't scald the milk on the hot saucepan); add cauliflower and heat to boiling. Reduce heat to low; cover and simmer until the cauliflower is tender (about 10 minutes).

3) In a blender, blend the cauliflower mixture at low speed in small batches until very smooth.

(it's smart to do this in small batches so you can remove the center cover of your blender to let some steam escape)

4) Return cauliflower mixture to saucepan; heat until steamy hot, stirring occasionally. Remove saucepan from heat; stir in mustard (with a whisk!) and 1 1/2 c cheese until melted and smooth. (if you add the cheese while the saucepan is still over heat it can make the cheese stringy) Garnish soup with remaining cheese to serve.

When I make this again I think I will substitute some of the cheddar cheese with pepperjack cheese to give it some "kick". We ate it with some french bread and it was so so yummy!