1) Preheat oven to 400 degrees. On a large sheet pan toss the onion, zucchini, mushrooms, bell pepper and garlic with the olive oil, salt and a pinch of pepper. Roast for 12-15 minutes, tossing halfway through.
2) Meanwhile, brush the flatbreads with olive oil, lay on a lightly greased sheet pan and set aside.
3) Remove veggies from oven and toss in a handful of fresh spinach. Bake the flatbreads for 3-4 minutes. Remove from oven and add the mozzarella, top with veggies and sprinkle on goat cheese. Place back in the oven and cook for 4-5 more minutes until cheese is melted. Slice and serve!