Add the tomatoes to a food processor and pulse on high about 20 to 25 times. The tomatoes should be smoother but still with some chunks. If you do not have a food processor you can use a blender or a food mill.
Mix in the basil and salt and serve.
Make-Ahead: You can make this recipe up to 2 days ahead of time.
How to Store: Cover and keep in the refrigerator for up to 6 days. Cover and freeze for up to 3 months. Thaw in the refrigerator for 1 day before using.
Having limited access to fresh san Marzano tomatoes in the states, I prefer to use canned.
If you want to use fresh Roma tomatoes or whole peeled canned tomatoes add a little sugar to them so that they can match the flavor of San Marzano tomatoes.