This recipe is based on one from The Healthy Jewish Cookbook, which my mother gave me last year. It's a very simple recipe, well-suited for making after a long day at work: sliced zucchini and tomato over a layer of shredded mozzerella on a bed of sauteed onion and garlic. The original recipe uses fresh mozzerella, but I've never seen fresh mozzerella certified kosher for Passover, so I made some changes to make it work with shredded mozzerella.
This recipe is not vegan (contains cheese), but it is gluten-free and non-gebrochts (contains no matzah). I suppose you could make it vegan by substituting some chopped or ground nuts for the cheeses, but I haven't tried that, so I don't know hwo well it would work.
