Preheat oven to 220 degrees C. Line 2 baking trays with baking paper. Spray, potatoes, kumara, capsicum, courgettes and onion with cooking spray then lay on the prepared baking trays. Roast in oven for 20 minutes. Add the tomato then bake an additional 10 minutes.
Heat oven griller to high then toast the bread on both sides. Sprinkle with Parmesan and toast again until melted and golden.
Serve vegetables on top of the spinach, drizzled with the dressing and the bread on the side.