In A Large Saucepan, Saute The Onion In Olive Oil Until Tender, But Not Browned. Chop The Tomatoes. Add To Sauted Onions. Stir In Remaining Ingredients. Heat To Boiling. Reduce Heat And Simmer 30 To 45 Minutes. Stir Frequently While Simmering. Note: Mixture Can Blended Until Smooth If Desired.