Add the can of San Marzano tomatoes, lightly rinse the tomato residue in the can with a small amount of fresh water then add this to the saucepan. Adjust the heat to medium low, add the spring of fresh basil.
Using a wooden spoon or spatula, break up the tomatoes into smaller pieces and simmer for 20 to 30 minutes. You will notice that the tomato will appear richer and separate somewhat from the olive oil. Remove the basis and sliced garlic, taste and season with salt if you so desire. Reserve in either the refrigerator or freezer for later use.
Recipe by LaBellaSorella at https://labellasorella.com/2015/01/marinara-sauce/