Preheat the oven to 200°C/180°C fan/gas 6.
Tumble the onions, squash and sprouts into a roasting tray, smother with 1 tablespoon of the oil, plenty of salt and pepper and roast in the oven for 25 minutes.
Add the cumin, cinnamon, chilli flakes, sumac, pitta and halloumi to the vegetables in the tray, toss with the remaining tablespoon of oil and bake for a further 15 minutes until the pitta is crispy and golden and the halloumi is brown on the outside but soft and pillowy in the centre.
Remove from the oven and serve sprinkled with extra sumac, fresh mint and an extra drizzle of oil.
Omit the baked halloumi to make this completely plant-based if you wish