Preheat oven to 190°C.
Place the cauliflower florets into a baking dish. Sprinkle with garam masala, salt and pepper and EVOO. Toss to combine. Roast for 30 minutes or until tender.
To make the sauce, place onion and EVOO into the Thermomix bowl. Chop 3 sec/speed 6. Saute 5 min/Varoma/speed 1. Add turmeric and chickpea flour. Cook 3 min/80°C/speed 1.
Add the kefir and salt. Cook 7 min/70°C/speed 2. Pour over cooked cauliflower and stir to coat. Sprinkle with coriander leaves.
To make the chilli oil, place EVOO into a small hot pan. Add cumin and mustard seeds. Heat until popping. Turn heat off and add chilli flakes. Infuse for 5 minutes before reheating and then drizzling all over the cauliflower. Serve immediately.