In a large pot or Dutch oven, heat a drizzle of olive oil over medium heat. Add the Italian sausage, breaking it apart with a wooden spoon. Cook for about 5-7 minutes until browned and cooked through.

Once the sausage is browned, introduce the diced onion to the pot, stirring frequently. Sauté for 3-4 minutes until the onions become translucent and fragrant. Add minced garlic and stir for an additional minute.

Next, incorporate the diced potatoes into the pot, followed by your chicken broth. Stir everything well and bring the mixture to a rolling boil over high heat. Once boiling, reduce heat to low, cover, and let simmer for 15 minutes or until the potatoes are fork-tender.

Reduce heat to low and gently stir in the heavy cream, then add the chopped kale or spinach, allowing them to wilt into the soup. Keep covered and simmer for another 2-3 minutes.

Finally, taste your soup and season with salt, black pepper, and a sprinkle of red pepper flakes to your liking. Ladle the soup into bowls and finish with a sprinkle of grated Parmesan cheese.