Check them one by one, remove the stalks and wash them very well, then dry them. Cut each tomato in half eliminating the green part of the stalks and the seeds.
Put the tomatoes in a steel sauce pan than put it on low heat covered; cook the tomatoes, turning occasionally, until they are mushy. Then put a masher on a bowl and mash all tomatoes and put the sauce on the fire again, add salt and oil and let it thicken until desired density. Then remove the pot from the stove, add the basil to the sauce.
the phase 2 will soon be available on the book "the secret of Italian cooking" in September on amazon.