Preheat the oven to 200C fan/gas mark 7.
Place the cauliflower in a roasting pan or baking dish. Place the tomatoes on top. Sprinkle with the garam masala, season with salt and toss to coat. Drizzle with 1 tablespoon of the oil and toss to coat evenly. Roast for 20-30 minutes, until golden brown and slightly charred. Stir the florets halfway through roasting.
While the cauliflower is roasting, place a deep, medium saucepan or casserole pot over medium-high heat. Add 1 tablespoon of the oil to the pan. Add the onions and sauté until they just start to turn translucent – 4-5 minutes. Add the turmeric and chilli powder and cook for 30 seconds. Lower the heat to medium-low and add the chickpea flour. Cook, stirring constantly, for 2-3 minutes. Lower the heat to a gentle simmer and fold in the kefir, stirring constantly.
Watch the liquid carefully as it cooks until it thickens slightly – 2-3 minutes. Fold the roasted cauliflower into the liquid and remove from the heat. Taste and add salt if necessary.
Heat a small frying pan over medium-high heat. Add the remaining 2 tablespoons of oil. Once the oil is hot, add the cumin and black mustard seeds and cook until they start to pop and the cumin starts to brown – 30-45 seconds. Remove from the heat and add the chilli flakes, swirling the oil in the pan until the oil turns red. Quickly pour the hot oil with the seeds over the cauliflower in the saucepan. Garnish with the chopped coriander and serve warm with rice or parathas.
1kg cauliflower, broken into bite-size florets
200g cherry tomatoes, halved
1.5 teaspoons garam masala
1 level teaspoon fine sea salt
60ml sunflower oil
200g red onion, finely chopped
1 teaspoon ground turmeric
1 level teaspoon Kashmiri chilli powder
1 rounded tablespoon chickpea flour
500ml fresh keffir/buttermilk/natural yoghurt
To finish
1 level teaspoon cumin seeds
1/2 teaspoon black mustard seeds
1 teaspoon red chilli flakes
2 tablespoons fresh chopped coriander