1. Preheat the oven to 400°F (200°C). Slice the zucchini lengthwise into thick “steaks” (about ½-inch thick). Brush both sides with olive oil and season with salt, pepper, and Italian seasoning.
2. Arrange the zucchini steaks on a parchment-lined baking sheet. Bake for 15 minutes, flipping halfway through, until tender and lightly golden.
3. In a small bowl, mix garlic, mozzarella, Parmesan, and red pepper flakes. Sprinkle the cheese mixture over the roasted zucchini.
4. Switch the oven to broil and cook for 2-3 minutes, until the cheese is melted, bubbly, and golden.
5. Remove from the oven, sprinkle with fresh parsley, and serve hot.