Provençal Vegetable Gâteau

This is a vegetarian special I came up with. It's visually appealing and quite tasty. Vegan and very nutritious.

Provençal Vegetable Gâteau
thinly sliced red onion (use a mandolin)
thinly sliced zucchini (use a mandolin)
thinly sliced tomato (use a mandolin)
salt, pepper, and oil, to taste
arugula pesto
oven-roasted cherry tomatoes
candied nuts

To assemble these gâteaux, I laid my three vegetables out in containers in front of me and chose an appropriately-sized round ring mold. I lined a baking sheet with parchment paper, and assembled the gâteaux, one at a time, If you have several identical ring molds, you can be more efficient and assemble a few at a time. 

I did my layers like this: red onion, zucchini, tomato, red onion, zucchini tomato, red onion zucchini. I used around 5-6 sliced of vegetables for each layer, depending on size. You could do more or less layers, depending upon how high you would like your vegetable stacks to be. 

To serve: gently use a flat spatula to transfer to a parchment-lined dish. Season with salt, pepper, and oil. Bake at 400◦F until heated through and vegetables are softened and tender. 
I served with arugula pesto drizzled around, seasoned oven-roasted tomatoes, and candied nuts.