Heat the olive oil in a large pot over medium heat, add the Italian sausage, and cook until browned, about 5-7 minutes. Remove with a slotted spoon, leaving drippings.

Add diced onion and minced garlic to the pot, sauté for about 5 minutes until the onion is translucent and fragrant.

Pour in the chicken broth and bring to a boil. Add sliced russet potatoes, then simmer for about 10 minutes until the potatoes are tender.

Return the sausage to the pot and add chopped kale. Simmer for an additional 5 minutes.

Stir in heavy cream and season with salt, pepper, and red pepper flakes. Adjust seasoning as needed.

Ladle into bowls and garnish with freshly grated Parmesan cheese.