Wash the tomatoes and remove the stems, which if cooked would make the sauce bitter. Place the tomatoes in a saucepan with just enough water to barely cover the bottom of the pan, cover, and bring to a boil over a medium-low flame. Simmer for 5 minutes, then drain well and cool slightly before passing through a food mill.
Discard skins and seeds.
Mince the onion and the parsley, and saute in the oil. When the onion begins to turn golden, add the tomato puree. Simmer for 15 to 20 minutes, salt to taste, and if the sauce seems too acid, add a pinch of sugar. In 1962 she made her first trip to Sicily, where she now lives with her husband and their two children.