Preheat your oven to 375°F (190°C).

Grease a 9x13-inch baking dish generously with olive oil or butter.

In a skillet over medium heat, add a splash of olive oil and sauté chopped onions and minced garlic for 3-4 minutes.

In a large mixing bowl, combine sliced zucchini, sweet corn, and halved cherry tomatoes. Add sautéed onion and garlic, seasoning with oregano, salt, and black pepper.

Spread the vegetable mixture evenly in your greased baking dish.

Sprinkle shredded mozzarella cheese generously over the vegetable mixture.

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

Lightly drizzle olive oil over the breadcrumb topping for extra crispiness.

Bake for 30-35 minutes, or until the top is golden brown and the vegetables are tender.

Remove from the oven and let cool for 5-10 minutes before serving, garnish with chopped basil or parsley.