Cheesy Broccoli Potato Soup

2 cups chicken broth

1/3 cup chopped onion

1 pkg (10 oz) frozen chopped broccoli

1 1/3 cups mashed potato flakes

2 cups cut up cooked chicken

2 cups shredded swiss cheese (8 oz)

2 cups milk

1/2 tsp salt

Heat broth, onion, and frozen broccoli to boiling in 3 quart saucepan.  Reduce heat; cover and simmer 5 minutes, stirring occasionally.  Stir in potatoes until well blended; stir in remaining ingredients.  Heat over low heat about 5 minutes, stirring occasionally, until hot and cheese is melted.