Potato & Swiss Cheese Recipe

I found this recipe on copykat.com.

I made this soup for a pot luck party at a friend's house and the responses were underwhelming (except for Judy J). So, I added this soup to my usual offering at work the following Wednesday. I brought this soup in addition to my Cream of Tomato. Well, the response from the crowd at work was great! The Potato & Swiss Cheese drew raves!! I was really pleased it was such a hit because the response from the pool party crowd really had me wondering. Here's the recipe for Potato & Swiss Cheese that serves about 10-12:

2 (32oz) cartons of Chicken or Vegetable Broth
2 lbs of Yukon Gold potatoes unpeeled and sliced thinly
1 yellow or red onion sliced thinly
1 qt of heavy cream
1 cup of shredded Swiss cheese
1/2 cup of grated Parmesan cheese (Trader Joe's Parmesan/Romano is the best)
1/4 cup of real bacon bits
2 tbsp green onions diced

Into a large pot pour the broth and yellow or red onions. Bring the pot to a boil and cook on medium for about 20 minutes until potatoes are tender. Add the cream, Swiss cheese, Parmesan cheese, bacon and green onions.

When I made this soup I added the Swiss cheese all at once by sprinkling it evenly over the top of the soup and then stirred the cheese into the soup. The cheese didn't melt into a creamy consistency the way I expected. It came out in clumps and had the consistency of clams when you chewed it. I looked online for some advice on using cheese in soups to see if I did something wrong but didn't find anything. Next time I make the soup I'm going to try adding the Swiss cheese a little at a time and see if that changes the consistency. If someone makes this soup I'd be interested in hearing how the cheese comes out.