Dice the onion, carrot, and celery. Mince the garlic. Add the onion, carrot, celery, and garlic to a large soup pot along with the olive oil. Sauté over medium heat until the onions soften (about 5 minutes).
Add the tomato paste and continue to stir and cook over medium heat for about three minutes more.
Add the crushed tomatoes, Italian seasoning, and vegetable broth to the pot. Stir to combine and dissolve any tomato paste off the bottom of the pot.
Turn the heat up to medium-high and bring the soup up to a simmer. Let the soup simmer for about 10 minutes, stirring occasionally.
Add the frozen tortellini to the soup and boil for about 3 minutes, or the recommended time on the package needed to cook the tortellini.
Turn the heat off. Stir the heavy cream into the soup. Stir the fresh spinach into the soup until wilted.
Taste the soup and season with salt and pepper to taste (we added about ¾ tsp salt and ¼ tsp pepper).