Heat oven to 180C/160C fan/gas 4. Mix the spices in a mixing bowl with 2 tbsp of the the oil and then add the cauliflower and toss until covered. Place on a baking tray and roast for 45 minutes turning halfway through.
Meanwhile, heat the remaining oil in a large pan. Fry the curry leaves and garlic for 1 min, making sure the garlic doesn’t brown. Add the tomatoes, chillies, sugar, lime juice and some seasoning. Cover with a lid and simmer for 15 mins until the tomatoes have broken down.
Add the roasted veg to the tomatoes. Simmer for 5 mins, adding a splash of water if the curry gets too thick. Stir through the coriander and serve with rice, warm naan and yogurt.