3 cheesy zucchini topping Recipes

olive oil, divided, pesto sauce , purchased (or your homemade), bread, cubed small (or torn, use up your stale white or whole wheat, french, just not sweet bread), white onion, small dice, zucchini, sliced 1/4 inch, corn , cut fresh off cobs or 2 cups frozen, sweet red pepper, diced, garlic clove, minced, mozzarella cheese, shredded

unsalted butter, plus extra for topping (start with 3, then see how much more you want to put in), yellow onions, cut in 1/2 and sliced, garlic cloves, minced (optional), zucchini, sliced 1/4-inch thick (about 4 zucchini), kosher salt (or sea salt to taste), fresh ground black pepper, ground nutmeg, all-purpose flour, hot milk, panko breadcrumbs (or italian breadcrumbs), grated gruyere cheese (or gouda, cheddar, swiss or parmesan)