This cheesy mushroom baked ziti is gluten-free, although with the stellar gluten-free pasta on the market nowadays, you certainly can't tell it is gluten-free. This recipe goes all out on the mushrooms, which are sauted with onions and parmesan, then added to a big bowl of cooked gluten-free rigatoni, and shredded mozzarella. Baked with additional cheese on top, this crowd-pleasing and can-feed-a-crowd dish is ready to come out of the oven in 25 minutes. For the meat lovers out there, feel free to add cooked italian sausage to this dish for an even heartier meal.