Sear the Sausage – In a large heavy-bottomed pot over medium heat, cook the Italian sausage, stirring occasionally and breaking it up as it cooks. This should take 8-10 minutes until the meat is browned. Drain excess grease if needed.
Sauté the Aromatics – Add diced onions and cook until they turn translucent (3-5 minutes).
Build the Base – Stir in diced tomatoes, tomato paste, chicken broth, garlic, Italian seasoning, salt, and pepper. Bring to a simmer.
The Finishing Touches – Add tortellini, heavy cream, and spinach. Stir to combine.
Let It Simmer – Allow the soup to cook until the tortellini is tender and the spinach is wilted (8-10 minutes).
Garnish & Serve – Ladle into bowls and top with shaved parmesan for the ultimate comfort dish.