Heat oil in 4-quart saucepan over medium heat until hot. Add onions and garlic. Cook until onions are tender.
Add all other ingredients, mix well. Bring to a boil, stirring occasionally. Reduce heat and let simmer for 1 hour, stirring occasionally (simmer time varies based on number of tomatoes. Could take as many as 4-5 hours to get correct consistency).
Ladle mixture into clean jars and cover with tight-fitting lids. Sauce can be refrigerated for up to 1 week or frozen for 3 months to 1 year.
*If you have extra green or red peppers on hand, you may add 1-2 for added flavor
*You may double or triple the recipe depending on the number of ripe tomatoes in your garden