This does make a fairly big batch that can be kept in the fridge for a couple of weeks. You can also freeze the sauce too.
CHEATS: Use 1.5 x 400 g/14.5 oz can diced tomatoes instead of fresh tomatoes. This will cut down your prep time.
For a runnier sauce, cook for less time. If you do leave the sauce runnier and want to thicken it with a glaze, use a little arrowroot flour mixed with water and add to the mixture while warm.