If you feel like a defective Italian, I feel like a defective half-Italian for not knowing how to make sauce from scratch even with canned tomatoes. (Canned tomatoes are extremely useful things, but other veggies in cans are scary.)

Hm...what about peeling them (trick involving poaching for a minute with a "x" cut into the bottom), then simmering? I'd heard of baked tomato sauce, but it was all the veggies mixed together then cooked as a sort of casserole.
Have you checked Joy of Cooking? Very useful book for stuff like this. So's Cook's Illustrated (America's Test Kitchens).