Heat 2 tablespoons olive oil in your large pot over medium heat. Add the diced onion and cook until translucent, about 5 minutes, stirring occasionally. Then add the minced garlic and sauté for another minute until fragrant but not browned.
Pour in the entire 28-ounce can of crushed tomatoes along with 4 cups of vegetable broth. Stir in 1 teaspoon dried basil and 1 teaspoon dried oregano. Season with salt and pepper to taste. Bring to a gentle boil, then reduce heat to low and simmer for 15 minutes.
Add the 9-ounce package of cheese tortellini directly into the pot. Cook according to package instructions, about 3 to 5 minutes, until tender and cooked through.
Turn heat to low and slowly stir in 1 cup heavy cream. Warm through without boiling to integrate the cream smoothly. Taste and adjust seasoning if needed.
Ladle soup into bowls and garnish generously with fresh basil leaves for a fragrant, herbaceous note.
