That's kind of how I make minestrone to be honest - when I'm in a hurry and not in the mood to make all the components from scratch. I just brown a little ground beef in a pot, then dump in a jar of marinara, a box of chicken stock, a few cups of frozen mixed vegetables (green beans, carrots, peas, onions, etc...), a can of kidney beans, some Ditalini pasta, then let it all simmer until the pasta is cooked all the way through. I may add a smidge of water if the soup is becoming too thick or condensed during the cooking process. But that's really about it.
It's also how I sometimes make "Italian Beef" in a slow cooker - just throw in a beef roast, some beef broth and a packet of dried Italian Dressing mix - then towards the end I may throw in a jar of Giardiniera (pickled vegetables).
I have yet to try the cake ones mentioned above, because I was nervous about them not mixing up properly, and winding up with dry spots of powdered cake mix. Does this sometimes happen?