Heat oil in a large saucepan over medium-high heat.
Add onions and saute until translucent.
Add garlic and saute for 1 minute, stirring constantly.
Stir in tomatoes (with juice) and simmer for 10 minutes.
Using a potato masher, crush the tomatoes until broken up into smaller pieces.
Simmer for another 10 minutes.
Add sugar, basil, crushed red pepper, black pepper and salt. [See Note 2]
Simmer for 15 minutes.
Use San Marzano tomato sauce in all your favorite Italian recipes, or serve over plain pasta! [See Note 3]
Video
Notes
Note 1: I like the balance the sugar provides! For natural sweetness, you can omit it or replace it with ¼ cup of shredded carrots.Note 2: Use fresh herbs when they are in season. Add ¼ cup of chopped fresh basil during the final minute of simmering (omit dried basil).Note 3: The sauce has a rustic, coarse texture. If you prefer a smoother sauce, use an immersion blender. Alternatively, let the sauce cool and use a regular blender.