My dad loved the breaded zucchini rounds!
For large ones, cut in half long way and scrap out the seeds. Make a stuffing, can be vegan or maybe sausage based, or even like spaghetti sauce and bake until the stuffing is cooked and the zucchini is fork tender. You might have to put just a tiny bit of water in the bottom of the pan for the last 15 minutes or so to help steam the zucchini if it is thick.
Last week I made a beef broth and then kept supplementing it with different ingredients, essentially turning it into a Pho type broth. On the last day, I cut a zucchini into rounds and cooked them along with thinly sliced steak (mushrooms also work).