01 - Heat olive oil in a large soup pot over medium heat. Add the Italian sausage, breaking it apart with a wooden spoon, and cook until evenly browned and no longer pink, approximately 5 to 6 minutes.
02 - Add the diced onion to the pot and sauté until softened and translucent, 3 to 4 minutes. Stir in the minced garlic and cook until fragrant, about 1 minute.
03 - Add the sliced potatoes, dried oregano, red pepper flakes, and chicken broth. Bring to a boil, then reduce the heat to low and simmer until the potatoes are fork-tender, approximately 12 to 15 minutes.
04 - Stir in the chopped kale and continue simmering until the leaves are wilted and tender, about 3 to 4 minutes.
05 - Reduce the heat to the lowest setting and stir in the heavy cream. Warm the soup through gently without bringing it to a boil. Season with salt and black pepper to taste.
06 - Ladle the soup into bowls and garnish with freshly grated Parmesan cheese and chopped parsley if desired. Serve hot.