Hidden Zucchini Mac and Cheese with Garlic Brown Butter Breadcrumbs is comfort food at its best. It's filled with an added veggie boost of grated zucchini, which disappears into the silkiest 3-cheese sauce. We've got Cheddar, fontina, and Gouda, and to top it all off, the mac and cheese gets topped with toasty garlic brown butter breadcrumbs!