Makes 11-half pint mason jars
In a large pot, heat the olive oil. Add onions and sauté until softened, but not browned, about 5 minutes. Add garlic and tomato paste. Cook for 10 minutes, until tomato paste has slightly browned. Add chopped fresh or whole canned tomatoes. Bring to very low boil, cover, and let simmer for 1 hour.
After 1 hour, take cover off and simmer for another hour - to reduce and thicken sauce.
At this point, if you are going to can the sauce using a water bath, prepare your jars and canner.
Once the sauce has been reduced, run through a food mill and adjust seasonings.
Add 1 tsp lemon juice to each half pint jar, then ladle sauce into jars, leaving a 1/2 inch headspace. Process for 35 minutes.
Each half pint jar makes 3 to 4 12-inch wood fired pizzas.