Heat oven to 220C/200C fan/gas 7. Cut the cauliflower into florets, saving the leaves. Tip the florets into a bowl and toss with the ground turmeric, cumin seeds, olive oil and a generous pinch of salt and pepper. Tip the cauliflower onto a baking tray, cook for 20 mins, then add the cauliflower leaves, give everything a good mix and cook for a further 5 mins. Spread the plain hummus onto a plate. Top with the roasted cauliflower and Bombay mix.