Heat the olive oil in a large Dutch oven or heavy-bottomed pot over medium-high heat.
Add the ground beef sausage and cook for 6-8 minutes, breaking it into small crumbles with a wooden spoon until browned and fully cooked.
Add the diced onion, carrots, and celery to the pot. Sauté for 5 minutes, stirring occasionally, until the onion is translucent and the vegetables begin to soften.
Stir in the minced garlic, tomato paste, dried oregano, and red pepper flakes. Cook for 2 minutes, stirring constantly, until the tomato paste darkens to a deep red and becomes fragrant.
Pour in the diced tomatoes (with their juices) and the chicken broth. Bring the mixture to a rolling boil.
Once boiling, reduce the heat to low. Cover and simmer for 15 minutes to allow the flavors to develop and the vegetables to become tender.
Increase the heat slightly to a gentle simmer. Add the refrigerated tortellini and cook for 3 to 5 minutes, or until the pasta is tender and floats to the surface (al dente).
Stir in the heavy cream and chopped baby spinach. Continue to cook for 1-2 minutes until the spinach is wilted and the soup is creamy and hot.
Taste and season with salt and black pepper. Ladle into bowls and garnish with freshly grated Parmesan cheese before serving.