Wisconsin Style Cheese Soup (NO velveeta here!!)

1/2 cup onion
1/2 cup butter
2/3 cup flour
1 teaspoon paprika
1 teaspoon salt
1 teaspoon ground mustard
4 cups milk
1 can Cream of Chicken soup
3/4 to 1 cup Chicken Broth
3 cups Cheddar Cheese (I used Sharp)
minced chives (optional)

Saute onions in butter til soft. Mix paprika, salt, ground mustard and flour together then add to onion butter mixture and cook for a few minutes to a paste. Gradually add milk and condensed soup. Cook and stir until thick, about 10 minutes. Add the cheese and chicken broth and cook til cheese is melted. Add more chicken broth to desired thickness. Garnish with chives. Serve with warm rolls or breadsticks. Makes about 2 quarts.