In a large pot over medium heat, remove the sausage from its casing and crumble it into the pot. Cook until browned, about 6-8 minutes. Drain excess fat if necessary.
Add the diced onion, carrots, and celery to the pot. Sauté for another 5 minutes or until the vegetables are soft.
Stir in the minced garlic and cook for an additional minute until fragrant.
Add the canned diced tomatoes (with their juice), chicken broth, dried oregano, dried basil, and red pepper flakes (if using) to the pot. Bring to a boil.
Reduce the heat and let the soup simmer for about 15 minutes, allowing the flavors to meld together.
Stir in the chopped kale or spinach and simmer for another 5 minutes until the greens are wilted.
Lower the heat and pour in the heavy cream, stirring gently to combine.
Add the grated Parmesan cheese, allowing it to melt into the soup. Season with salt and pepper to taste.
Serve hot, garnished with fresh parsley.
Notes
Adjust the spice level by choosing mild or spicy sausage.
Keyword cheesy, comfort food, Italian sausage, soup