Souper Saturday--Spinach Bisque

So, like many of my soup recipes--this is NOT lowfat but it's full of spinach, that's healthy right?

Spinach Bisque

4 cups chicken broth

2 pkg. frozen spinach

4 Tbsp. butter

2 Tbsp. onion, chopped

4 Tbsp. cornstarch

2 cups cheddar cheese, grated

2 Tbsp. parmesan cheese, grated

2 cups milk

salt and pepper to taste

Boil spinach in chicken broth until tender (10-15 minutes).  Meanwhile, saute onion in butter until soft.  Add corn starch until well blended.  Add onions to spinach.  Stir in the cheeses and milk.  Salt and pepper to taste.  Cook over medium heat until heated through.