wash, destem, and cut large tomatoes in half. blend lightly- my goal is to break them up, but still have pieces. bring to a boil and boil over medium heat, stirring as needed (i start by setting the timer for 8 minutes and slowly decrease the time between stirring down to about 4 minutes). boil down to desired thickness (time needed will depend on the consistency and amount of tomatoes used). pour into jars, label with date (i just label the month), and let cool before storing in freezer.
(also this would work well with all the in season tomatoes from the farmers market…go close to closing and i bet you could get a good deal on the ones they don't want to pack up and take back home!)