Making Zuppa Toscana is easy when you follow these straightforward steps:

1. Sauté the Sausage: In a large pot, heat olive oil over medium heat. Add the Italian sausage and cook until browned, breaking it up with a spoon as it cooks (about 6-8 minutes).

2. Add Onions and Garlic: Stir in the diced onion and minced garlic. Cook for an additional 2-3 minutes until the onion is translucent.

3. Incorporate Broth and Potatoes: Pour in the chicken broth and add the sliced potatoes. Bring the mixture to a boil, then reduce the heat to a simmer.

4. Simmer: Let it simmer for about 15 minutes or until the potatoes are fork-tender.

5. Mix in the Cream: Add heavy cream to the pot and stir well. Bring back to a gentle simmer.

6. Add Kale and Season: Stir in the kale and red pepper flakes (if using). Cook for an additional 5 minutes until the kale is wilted. Season with salt and pepper to taste.

7. Serve: Ladle the soup into bowls, and sprinkle with grated Parmesan cheese if desired.

Following these steps will lead you to a bowl of delicious Zuppa Toscana that is sure to impress!