In a large pot over medium heat, add the ground sausage. Cook, stirring occasionally, for about 8-10 minutes, or until the meat is no longer pink. Drain excess grease and set aside.
Add onions to the pot and cook until softened (about 3-5 minutes).
Add the tomatoes, tomato paste, chicken broth, garlic, Italian seasoning, salt, and pepper. Stir and bring to a simmer.
Add tortellini, heavy cream, and spinach. Stir to combine.
Simmer until the tortellini is soft and the spinach is wilted (about 8-10 minutes).
Garnish with parmesan.