Here's a way to make tomato sauce without the usual need for endless stirring. You can do this by using a slow cooker(crock pot) during the final cookdown.
Do the initial cooking on the stove in a heavy pot and then pour into a blender or food processor to puree.
Pour the pureed sauce into a crock pot set at high.
Keep the lid off which will allow the water to evaporate. A few hours later you will have a nice thick sauce that required no stirring.