In a large Dutch oven or stockpot, warm olive oil over medium-high heat. Add carrots and onion, and cook for about 5 minutes, stirring often. Add garlic and tomato paste and cook, stirring often, for about 1 minute more, then stir in the diced tomatoes, Italian seasoning, and salt.
Add the broth, increase heat, and bring the mixture to a boil. Add tortellini and cook according to package directions.
When the tortellini is done, turn off the heat, and stir in the spinach and cream. Sample a spoonful and season with extra salt and/or black pepper, to taste. Serve with grated Parmesan, if desired.
Notes
On Salting: For our tastes, I find that 1/2 teaspoon table salt is just right if using diced tomatoes that also have salt in them. If using no salt diced tomatoes, I add extra salt to the soup, usually 3/4-1 teaspoon in total.