Step 1: Brown the Sausage

1. Heat a large pot or Dutch oven over medium heat. Add the Italian sausage and cook, breaking it into small pieces, until browned and fully cooked (about 5–7 minutes).
2. Remove the sausage with a slotted spoon and set it aside. Drain excess grease from the pot, leaving about 1 tablespoon behind. If the sausage is lean, add 1 tablespoon of olive oil.

Step 2: Sauté the Vegetables

1. Add the diced onion, carrots, and celery to the pot. Sauté for 5–7 minutes until softened.
2. Stir in the minced garlic, Italian seasoning, and red pepper flakes (if using), cooking for another 1–2 minutes until fragrant.

Step 3: Add the Broth

1. Pour in the chicken broth, scraping up any browned bits from the bottom of the pot to deglaze.
2. Bring the mixture to a gentle simmer and cook for 10 minutes, allowing the flavors to meld.

Step 4: Add the Cream and Parmesan

1. Reduce the heat to low and stir in the heavy cream and Parmesan cheese. Stir until the cheese is melted and the broth is smooth and creamy.

Step 5: Add the Sausage and Greens

1. Return the cooked sausage to the pot and stir in the spinach or kale. Simmer for 3–5 minutes until the greens are wilted and tender.
2. Taste the soup and adjust the seasoning with salt and black pepper as needed.

Step 6: Serve

1. Ladle the soup into bowls and garnish with additional Parmesan cheese, if desired.
2. Serve hot with crusty bread for dipping.