In a large pot, heat the olive oil over medium heat. Add the diced onion and sauté until translucent, about 5 minutes.
Stir in the minced garlic and cook for an additional minute, until fragrant.
Pour in the crushed tomatoes and vegetable broth, and sprinkle in the dried oregano and basil. Season with salt and pepper to taste. Stir well to combine.
Bring the soup to a gentle boil, then reduce the heat and simmer for 15 minutes to allow the flavors to meld.
Add the tortellini to the pot and cook according to the package instructions, usually around 5-7 minutes, until tender.
Once the tortellini is cooked, stir in the heavy cream and chopped fresh basil. Cook for an additional 2-3 minutes, warming through. Adjust seasoning if necessary.
Serve hot in bowls, topped with grated Parmesan cheese and a sprinkle of basil for garnish.
Notes
Serve the soup in deep bowls with a sprig of fresh basil on top and a drizzle of olive oil for added elegance.