Put the sausage and onion into a large soup pot. On medium heat, brown the sausage and onion. I like to let mine get a little "crisp" around the edges, it seems to hold together better in the soup. Once the meat is cooked you will need to drain it, because it will have a lot of grease on it. You can even rinse it if you want, but I just normally drain it. Set aside sausage.
Wash the potatoes really well, and then dice with the skin on. To the pot you just cooked the Sausage in add: chicken broth, diced potatoes, salt and pepper. If you want to spice up add red pepper flakes. Add cream. It is important to add the cream while the broth is still cool otherwise the cream will curdle. Now add the drained, cook sausage back to the pot, and turn on medium heat. Slowing bring to a boil over medium heat, stirring every few minutes so you do not scald the cream. Once it comes to a boil turn down to medium-low heat so it can simmer for 20 minutes.
While your soup in simmering, wash the Kale very well, it has lots of green leaves for dirt to hide in.
Once you have washed it, take off the stock, it is not very good for eating. You just want the Kale leaf. Then chop the kale into small bite sized pieces. You will need about 6 cups, uncooked.
Once the soup has been simmering for 20 min., add the kale, cover again and simmer another 30 mins. You will see the soup has a orange look to it, that is from the little bit of grease left from cooking the sausage, it is just a light layer but stays on top the pot.
You can top with a little bit of grated cheese, and enjoy!