this is my usual method for freezing home-made tomato sauce for pizzas and whatever else comes to menu. it's just quartered tomatoes - with skin on - two large onions in half-slices, salt and pepper. I have been known to slice in an excess sweet/bell pepper - but they are not really producing well this year.
an eight quart pot - had to squish them done with the lid. I use a lid for a couple minutes to "steam" the tomato softer:
several hours later:
and finally a whole two quarts (! 25% of the initial volume) frozen into flat bricks - makes for easy storage.