Heat the oven to 425°. Place each piece of naan on a large baking sheet. Spread 1/4 cup pizza sauce on each, leaving a 1/2-inch border. Sprinkle the Parmesan and mozzarella on top.
Layer on the vegetables in a rainbow pattern as shown. Drizzle each pizza with a teaspoon of the olive oil and sprinkle with the Italian seasoning.
Bake the pizzas until the vegetables are tender and the crust is slightly golden, about 20 minutes. Let them cool slightly. If you like, sprinkle on more Parmesan, then slice and serve.