I live in Italy and right now we have a glut of tomatoes. I thought people might be interested on how to make the classic tomato sauce from scratch.
Put all the washed tomatoes in a big, heavy based, saucepan and add a whole onion and a sprig of basil.
Let the tomatoes come to the boil, making sure not to burn the base of the pan (I squash a few tomatoes with a spoon to release the liquid at the beginning of the cooking).
Keep it bubbling away and reducing for about an hour and then put the whole thing through a mouli, to remove skins and seeds.
Heat up a generous amount of olive oil in a pan and add a small amount of very finely chopped onions. When these have cooked add the passata, some more basil and some salt.
Let the sauce come to the boil and then lower the heat and simmer until the sauce has reduced down to how you like it.
This tomato sauce is the basis of Italian cuisine and made in this way is liquid health. It can be preserved by bagna maria- boiling up sealed jars.
Hope this helps, post if you have any questions.