Preheat the oven to 400 degrees Fahrenheit (200 degrees Celsius). Spray a large-rimmed baking sheet with olive oil to prevent sticking.
Place the sliced zucchini, onion, bell peppers, and broccoli on the prepared baking sheet. It's okay if they overlap slightly. Drizzle the veggies generously with olive oil, and season with salt and pepper to taste.
1 zucchini, 1 onion, 2 bell peppers, 3 small crowns broccoli, 3 Tablespoons olive oil, Salt to taste, Black pepper to taste, 1 yellow squash
Bake the vegetables in the preheated oven for 20 minutes.
In the meantime, prepare the Parmesan mixture. In a medium bowl, whisk together the grated Parmesan cheese, breadcrumbs (or almond flour), oregano, salt, and pepper.
1 cup parmesan cheese, 1/2 cup breadcrumbs, 2 teaspoons dried oregano, Salt to taste, Black pepper to taste
After the initial 20 minutes of roasting, remove the baking sheet from the oven and toss the veggies to mix them up. If there is excess liquid in the pan, use some paper towels to absorb most of it. Push the veggies together to form an even single-layer rectangle.
Drizzle the roasted vegetables with the marinara sauce, making sure to coat them evenly.
1 cup marinara sauce
Sprinkle the prepared Parmesan mixture all over the veggies, ensuring they are well-covered. The mixture will help absorb any remaining liquids.
Next, add the shredded Mozzarella cheese on top of the veggies.
2 cups Mozzarella cheese
Drizzle some additional olive oil over the cheese and vegetables.
Place the baking sheet back into the oven, and continue to bake for an additional 18-20 minutes or until the cheese is melted and bubbly, and the vegetables are tender.
Once the bake is done, remove it from the oven. If desired, garnish with chopped basil and chili pepper flakes for extra flavor and a pop of color.
Optional garnish: chili pepper flakes
Serve the veggie pizza immediately as a main course or side dish.
Store leftovers in an airtight container in the fridge for 2-3 days.