Heat olive oil at medium heat in a 6 or 8-ounce Dutch oven or soup pan.
Add onions and cook for 2-3 minutes
Add garlic and cook for another 2 minutes.
Stir in tomato paste.
Add the San Marzano tomatoes 1 can at a time. After you add the first can, use a potato masher to gently crush the tomatoes. Repeat crushing after you add the second can.
Add the tomato sauce, beef broth, and wine.
Add the Italian seasoning, sugar, red pepper flakes, and fresh basil
Bring to a boil, reduce heat and simmer for 3 hours.