will be to use some sort of pre-jarred tomato sauce.
I agree. At least, the flavors in those have been together for a good while. You can definitely make something decent with one of those. Just read the ingredients and don't buy one with meat already in it. Taste it when you open the jar to see what flavors are predominant and how salty it is before adding seasonings.
You can do a quick cooking sauce but you might have to add tomato paste as a thickener and that really should cook a bit longer than an after work special. However, if you take the time to brown a little paste and then add a jarred sauce or even crushed tomatoes, you'll at least have some of that browned paste flavor if you like that.