Add the olive oil and butter to a soup pot over medium heat. Once the butter has melted, add the onion and sauté it for 5-7 minutes.
Stir in the garlic and flour, and cook it for about a minute.
Stir (or whisk) in the chicken broth until the flour has dissolved.
Add the canned tomatoes, Italian seasoning, sugar, and cream to the pot. Increase the heat to high and bring it to a gentle boil.
Once the soup is boiling, add the tortellini and reduce the heat to a simmer. Let it cook for 8 minutes. Season with salt & pepper as needed. If using the fresh basil, tear it into small pieces and add it in a few minutes prior to serving.
