Cut the cauliflower into medium-sized florets and toss them with the spices and cornflour. Season with salt and freshly ground pepper too, and toss with a little oil.
Spread the florets on a baking tray lined with baking paper and roast in a preheated oven at 225°C, conventional (top and bottom heat), for about 20 minutes - turning them once along the way.
Meanwhile, make your hummus and spread it over a serving plate.
Mix the ingredients for the parsley oil too, and season to taste with salt and freshly ground pepper.
Arrange the slightly cooled cauliflower on top of the hummus. Drizzle with the parsley oil and season with freshly ground pepper before serving.