Heat olive oil in a large soup pot over medium heat.
Add chopped onion and sauté until soft and translucent.
Stir in minced garlic and cook until fragrant.
Add crushed tomatoes and vegetable broth to the pot.
Season with Italian seasoning, salt, and black pepper.
Bring the soup to a gentle boil, then reduce heat and simmer for 15 minutes.
Stir in heavy cream and mix until fully combined.
Add cheese tortellini and cook according to package instructions.
Taste and adjust seasoning if needed.
Remove from heat and garnish with fresh basil and Parmesan cheese.