Roasted vegetable curry

INGREDIENTS1 large sweet potato, peeled and cubed (or use 1 medium cauliflower broken into florets)1 butternut, peeled and cubed4 baby marrows, sliced1 aubergine, cubed2 large red peppers, cored and cut into chunks90ml tikka masala paste60ml (4 tbsp) oil2 large onions, chopped1x 400g can chopped tomatoes1 x 400g can coconut milkFresh coriander, to serve as garnishMETHODPreheat the oven to 180°C.