Gently crush the tomatoes and set aside. Be sure to save the puree from the can. Alternatively, you can use already crushed tomatoes if you can find them.
Add olive oil to a medium saucepan or skillet. Heat on medium heat. Add the onions and cook until translucent. Add the minced garlic and cook stirring for about 2 minutes.
Add the tomatoes, with the puree, salt, pepper, and oregano (and red pepper, if using). Bring to a simmer and cook for 30 minutes stirring occasionally. After 30 minutes taste for salt and pepper and reduce down to desired consistency.
Serve over pasta and garnish with fresh basil.
The cooled sauce can be stored in an airtight container in the fridge for 5 to 7 days.
To freeze, store in an airtight container or plastic freezer bag. Freeze for up to 3 months.
San Marzano Tomato Sauce https://www.peelwithzeal.com/san-marzano-tomato-sauce/