Preheat your oven to 375°F (190°C) and grease a 9x13-inch baking dish with olive oil or butter.

In a large skillet, heat olive oil over medium heat. Sauté onion and garlic for 3-4 minutes until translucent.

In a mixing bowl, combine zucchini, corn, cherry tomatoes, onion, and garlic mixture. Season with oregano, salt, and pepper.

Transfer the vegetable mixture into the greased baking dish evenly.

Sprinkle shredded mozzarella cheese over the vegetables.

In a bowl, mix Parmesan cheese with panko breadcrumbs, then sprinkle this over the mozzarella layer.

Drizzle olive oil over the breadcrumb topping.

Bake for 30-35 minutes until the topping is golden brown and the edges are bubbling.

Let it cool for 5-10 minutes before slicing.

Garnish with freshly chopped basil or parsley before serving.