1. Heat the olive oil in a large pot or Dutch oven over medium heat. Add the chopped yellow onion and cook, stirring occasionally, until it softens and becomes translucent, which usually takes about 5-7 minutes.

2. Stir in the minced garlic and cook for just 1 minute more until fragrant. Pour in the crushed tomatoes, stirring well to combine with the onion and garlic.

3. Add the vegetable broth to the pot. Bring the mixture to a gentle simmer, then reduce the heat to low, cover, and let it cook for about 10 minutes.

4. Stir in the heavy cream, fresh chopped basil, salt, black pepper, and optional red pepper flakes. Mix everything until well combined.

5. Increase the heat to medium-low and add the refrigerated cheese tortellini directly into the simmering soup. Cook according to package directions, typically 2-3 minutes, or until the tortellini are tender and float to the surface.

6. Taste the soup and adjust the seasonings if needed.

7. Ladle the hot soup into bowls. Garnish each serving with extra fresh chopped basil and a generous sprinkle of grated Parmesan cheese. Serve immediately.